School Science Lessons
Topic 3 Laboratory Safety
2012-05-09 SPwp
Please send comments to: J.Elfick@uq.edu.au
See: Part 18. Interesting websites, Safety, Laboratory safety
Teachers of science in the State of Queensland, Australia, must refer to the latest version of the guidelines "Aspects of Science Management: A Reference Manual for Schools" prepared by the Education Services Directorate, Education Queensland (PO Box 33, Brisbane), Albert Street, Qld. 4002, Australia.
Table of contents
3.0 Laboratory Safety
22.6.3 Bunsen burner safety
15.10.0 Chemicals Not permitted in schools
3.4.0 Chemicals safety
15.9.0 Cryogenic solids and liquids
3.2.0 Duties of a teacher
3.3.0 Equipment safety
3.9.3 Expired air resuscitation (EAR) and Cardiopulmonary resuscitation (CPR)
3.5.0 Fire safety
15.7.0 Flammable organic chemicals
15.8.0 Flammable organic chemicals with low flashpoint below 32oC
15.1.0 Hazard classifications: Explosive, Flammable, Oxidizing, Poison, Harmful, Corrosive, Irritant
15.5.0 Hazard classifications used by NSW Department of Education and Training, (DET), Australia
3.8.0 Hazards associated with gases
3.7.0 Hazards of anion compounds
15.2.0 Health effects of chemicals
15.3.0 Laboratory safety and hazardous chemicals
7.0.0 Laboratory safety for physics teaching
7.5.0 Laser safety
2.0 Microbiology safety
4.0.0 Physical hazards (Draft Australian criteria for the classification of hazardous chemicals)
List 1D Personal protective equipment
27.1.0b Radiation hazards
7.2.0 Radiation hazards, Modes of radiation exposure
3.9.1 Swimming pools, checklist of daily routine for the pool operator
3.9.2 Swimming pools, pool test ranges
18.7.0 Swimming pools chemistry
3.6.0 Toxicity, Metals and metal compounds
3.10.0 Toxicity, Poisons and FIRST AID
3.1.0 Workplace Health and Safety Act, 1995, State of Queensland, Australia
3.1.0 Workplace Health and Safety Act, 1995, State of Queensland, Australia
3.1.1 Department of Education, State of Queensland, Australia
3.1.4 Hazard classification and experiments
3.1.5 Laboratory organization
3.1.2 Risk Assessment
3.1.3 Teacher Responsibility
3.2.0 Duties of a teacher
3.2.5 Biological hazards and use of live animals
3.2.3 Experimental procedures
3.2.1.1 Laboratory notice
3.2.2 Protective clothing
3.2.1 Supervision of students
3.2.4 Teach manipulative skills
3.3.0 Equipment safety
3.3.5 Carbon dioxide syphon bulbs
3.3.3 Eye-washing and safety shower
3.3.2 Fume cupboards, fume chambers, fume hoods
3.3.6 Glass wool
3.3.4 Mercury in barometers and thermometers
3.3.1 Test-tubes, glassware and microscope slides
3.4.0 Chemicals safety
3.4.12 Chemicals spill kit
3.4.7 Chemicals swallowed
3.4.8 Chemical vapours and smelling chemicals
3.2 Copper residues
3.4.1 Correct names of chemicals
3.4.4 Corrosive substances
3.4.11 Disposal of waste chemicals
3.4.6 Gas or vapour inhalation, EAR, CPR
3.4.10 Handling and transferring chemicals
3.1 Hydrogen sulfide, warning when treating residues
3.3 Lead residues
3.4 Mercury residues
3.5 Organic liquid residues
3.4.3 Prepare dilute acids and bases
3.4.2 Quantity of chemical to be used in experiments
3.6 Silver residues
3.4.5 Skin contamination
3.4.13 Storing chemicals
3.4.9 Tasting chemicals
3.7 Zinc residues
3.4.13 Storing chemicals
1.0. Store acids
2.0. Store alkalis
4.0. Store flammable liquids
5.0. Store hygroscopic substances
6.0. Store organic chemicals
7.0. Store oxidizing agents
8.0. Store reagent bottles and stock bottles
9.0. Store sodium and potassium
10.0. Store sodium chlorate and potassium chlorate
3.5.0 Fire safety
3.5.1 Action in case of fire - evacuation
3.5.2 Action in case of fire - equipment
3.5.6 Burning fat in a frying pan
3.5.5 Clothes on fire
3.5.10 Combustible solids
3.5.3 Electrical fires
3.5.4 Fire prevention - possible sources of ignition
3.5.11 Fireproof cloth
3.5.9 Flammable gases
3.5.8 Flammable liquids
3.5.7 Flammable substances
3.6.0 Toxicity, Metals and metal compounds
3.6.1 Aluminium toxicity
3.6.2 Barium toxicity
3.6.3 Boron toxicity
3.6.4 Calcium toxicity
3.6.5 Chromium, chromic acid toxicity
3.6.6 Cobalt toxicity
3.6.7 Copper toxicity
3.6.8 Lead toxicity
3.6.9 Magnesium toxicity
3.6.10 Mercury toxicity
3.6.11 Nickel toxicity
3.6.12 Potassium toxicity
3.6.13 Silver toxicity
3.6.14 Sodium toxicity
3.6.15 Strontium toxicity
3.6.16 Zinc toxicity
3.7.0 Hazards of anion compounds
3.7.1 Bromides
3.7.2 Chlorates
3.7.3 Chlorides
3.7.4 Chromates
3.7.5 Ferricyanides
3.7.6 Ferrocyanides
3.7.7 Hypochlorites
3.7.8 Iodates
3.7.9 Iodides, iodine allergy
3.7.10 Nitrates
3.7.11 Oxalates
3.7.12 Permanganates
3.7.13 Peroxides
3.7.14 Phosphates
3.7.15 Sulfates
3.7.16 Sulfides
3.7.17 Sulfites
3.7.18 Thiocyanates
3.7.19 Thiosulfates
3.8.0 Hazards associated with gases
3.8.1 Ammonia, anhydrous
3.8.2 Carbon dioxide
3.8.3 Carbon monoxide
3.8.4 Chlorine
3.8.5 Hydrogen gas
3.8.6 Hydrogen chloride, anhydrous
3.8.7 Hydrogen sulfide
3.8.8 LP gas (bottled gas)
3.8.9 Natural gas
3.1.0 Workplace Health and Safety Act, 1995, State of Queensland, Australia
3.1.1 Department of Education, State of Queensland, Australia
The Department of Education is committed to providing and maintaining a healthy and safe work and earning environment for all employees, students and others. The department has a statutory responsibility under the Workplace Health and Safety Act (2005) to ensure the risk of disease or injury from the school or workplace is minimized for all persons in contact with the school or other departmental workplace. Principals, teachers, and all other employees and persons at the school have an obligation for ensuring workplace health and safety at the school. In particular, the Workplace Health and Safety Act 1995 places a statutory obligation on employees and other persons at the school to follow instructions for workplace health and safety, use personal protective equipment and behave responsibly in regard to workplace health and safety while at school or involved in school activities.
Obligations for workplace health and safety should be ensured by:
1. identifying hazards,
2. assessing risks that may result because of the hazards,
3. deciding on control measures to prevent, or minimize the level of, the risks,
4. implementing control measures, and
5. monitoring and reviewing the effectiveness of the measures.
3.1.2 Risk assessment
Once a hazard has been identified, the consequences associated with it need to be determined. In schools, the most likely effects to consider would be those that involve direct injury, e.g. cuts, burns, electrocution and poisoning. Less likely effects might also include those arising from longer term exposure, e.g. exposure to materials containing asbestos. Risk assessments may vary in complexity depending on the nature and location of the hazardous situation, the personnel and equipment available, and the age and number of
students present. The underlying principle of all risk assessments is the consideration of consequences of the hazardous outcome and the probability or frequency of the occurrence. In general, when a learning / teaching activity occurs in the teaching of science, the risk is related to the probability of an injury or illness occurring, the duration and frequency of exposure to the hazard, and the consequence or outcome of something going wrong.
The two major types of risk assessment
1. The potential effects of hazards that are immediate or acute. These include hazards that are mechanical, electrical, penetrating injuries and some forms of manual handling.
2. The potential effects of hazards that are chronic or long-term hazards. These include hazards that involve noise, hazardous substances / chemicals, repetitive movements and constrained postures.
Teachers of science should refer to the relevant risk assessment details in HS-10: Workplace Health and Safety
3.1.3 Teacher responsibility
In accordance with the Department of Education Manual module HS-07: Occupational Health and Safety, teachers are responsible for the health and safety of students while on school premises and participating in official school activities, wherever these may take place.
Teachers should:
(a) maintain healthy and safe procedures and practices,
(b). collaborate with Regional Occupational Health and Safety Consultants, employees of Education Queensland, workplace health and safety representatives or workplace health and safety committees to assess hazards which exist in the school or workplace, and to eliminate or reduce the associated risks as required,
(c) identify hazards and minimize risks in science teaching areas,
(d) ensure that employees, students and other users of educational facilities receive appropriate workplace health and safety information and training (see your School Health and Safety Officer or Principal),
(e) take care to ensure that appropriate use is made of all safeguards, safety devices, personal protective equipment and other appliances provided for health and safety,
(f) manage behaviour of students (including school ground and excursion activities),
(g). ensure all work injuries, work related illnesses and dangerous occurrences at the workplace are recorded. Such records are to be completed and dispatched to the appropriate authorities within the designated period (see your Principal or Registrar),
(h) ensure special needs groups, e.g. people with disabilities and persons from non-English speaking backgrounds, are considered in regard to workplace health and safety issues.
3.1.4 Hazard classification and experiments
See 15.1.0: Hazard classifications: Explosive, Flammable, Oxidizing, Poison, Harmful, Corrosive, Irritant
1. The experiments in this document do not require the use of any chemicals with the following hazard classifications:
Explosive, Oxidizing, Toxic, Radioactive, Highly flammable or Extremely flammable (flash point 21oC) or any chemical specified in the Schedule 1 of the Poison Rules, UK. However, some experiments requiring the use of propanone, acetone, as a solvent are included.
2. Preparations of small amounts of some dangerous gases are included on the assumption that only experienced science teachers do the experiment and direct observation of these gases has educational value. These experiments contain the warning: "BE CAREFUL!". This experiment must be done in a fume cupboard.
1. Another criterion for including some limited handling of dangerous substances by experienced teachers is that students may experience these substances in their daily lives. Propanone (acetone) was used for nail polish remover but is being phased out in the modern cosmetic industry. Chlorine compounds are used for bleaches and water disinfectants. Sulfuric acid is used in a motor car battery.
4. The warning "Be careful" is used in this document where experiments or procedures require special care. However, the experiments described have been selected on the basis that a trained science teacher practises them before deciding whether to include them in the teaching programme. The trained science teacher who has the duty of care must decide which students are allowed to do the experiments themselves and under what conditions.
3.1.5 Laboratory organization
1. Equipment and chemicals are stored in a systematic, orderly and a neat manner.
2. Equipment and chemicals borrowed from a preparation room or storage area is returned to the assigned place.
3. Teaching and storage rooms are uncluttered with no equipment protruding over benches, no dangling wires and no equipment stored on the floor.
4. Bench tops are always clean. Any spillage is wiped up immediately.
5. Reagent bottles are clearly labelled and filled regularly.
6. Sinks are clean and not blocked with waste.
7. Separate waste bins are used for broken glass (which must be wrapped) for paper, for cloth and for solid chemical residues.
8. Water outlets, gas turrets on the benches, power outlets and electrical switches are in good working order.
9. The laboratory and storeroom doors are locked when not occupied.
10. Time is allowed for all the above.
3.2.0 Duties of a teacher
Teachers should select school science lessons and laboratory experiences that are appropriate to the student group and the level of learning. When selecting laboratory experiences the teacher must check that school authorities approve the activity. This document contains suggestions for practical teaching by a trained science teacher. After choosing an experiment, the teacher should practise it in the preparation room before demonstrating it to students or before requiring students to do it. The teacher has the duty of making the decision about whether the experiment is safe for the children in the classroom or laboratory.
The level of risk of injury to students and teacher will vary from school to school, depending on:
1. expertise of the teacher,
2. size of the student group,
3. diversity of students, and
4. the facilities and equipment.
3.2.1 Supervision of students
Supervision of students must be continuous and vigilant so that unauthorized or inappropriate behaviour does not lead to accidents resulting in physical injury, fires or other dangers. Teachers must choose a set of laboratory rules to be prominently displayed and with copies given to students. Students must know the rule and understand them.
Teachers must pay particular attention to the following rules:
1. Students do not enter any laboratory or storeroom unless a teacher is present.
2. Students do not eat or drink in the laboratory or storeroom.
3. Students do not taste chemicals.
4. Students must behave in a careful and businesslike manner.
5. Students are safely seated and not crowded, with fellow students, chemicals and glassware not within "elbow width".
3.2.1.1 Laboratory notice
Keep the laboratory safe and sealed!
+ Close the windows
+ Lock away all the equipment
+ Turn off lights, equipment and computers
+ Lock all doors
3.2.2 Protective clothing
1. Students in chemistry classes should wear strong shoes and take care of unbuttoned long sleeves and long hair. Students must wear protective clothing, e.g. aprons, safety glasses and nitrile chemical-resistant gloves when chemicals are being handled. Teachers should be aware of students who wear contact lenses.
2. Safety spectacles, | safety goggles
Students should wear safety spectacles or safety goggles if the experimne could propel chemicals into the eyes. Students wearing prescription glasses should change to use safety glasses. There is always the danger of hot or caustic materials being splashed into the eyes.
3. Safety gloves
Many schools require students to wear heavy gloves, safety spectacles or safety goggles, and closed shoes for all experiments. The four kinds of gloves are as follows:
2.1 Disposable surgical gloves, which are used during dissections, handling animal tissue and blood products, but not for chemicals,
2.2 Rubber washing-up gloves, which are not designed to protect against concentrated chemicals or organic solvents, e.g. acetone,
2.3 Nitrile chemical-resistant gloves, which are designed for handling concentrated acids and organic solvents,
2.4 Insulated heat-proof gloves.
3. Students must use safety glasses and nitrile chemical-resistant gloves if the school allows them to dilute concentrated acids or bases and when heating chemicals to avoid the danger of hot or caustic materials being splashed into the eyes. Students must wear insulated heat-proof gloves and aprons if the activity could result in damage to their hands or body. Pay attention to unconfined long hair, jewellery, ties, unbuttoned long sleeves and loose clothing. Synthetic garments that may be a fire hazard. Students in chemistry classes should wear strong shoes that completely cover the feet and protect them from spilt corrosive or hot liquids. Students may not wear sandals.
3.2.3 Experimental procedures
1. Read the label on reagent bottles twice to avoid errors.
2. Always follow exactly the instructions for chemical experiments.
3. Do not substitute another chemical for chemicals specified in the experiment instructions.
4. Always add a solid to a liquid reagent to achieve better control of gases that form in the reaction.
5. Do not let students do unauthorized experiments. Some chemicals are safe by themselves, but they may form explosive mixtures when mixed with oxidizing agents, e.g. sulfur, sucrose (cane sugar) and powdered zinc.
6. This document does not recommend the use of gas generators, e.g. Kipp's apparatus.
3.2.4 Teach manipulative skills
Teachers should teach the necessary manipulative skills by demonstration before asking students to use the skills in an experiment. These skills include heating of liquids or solids in test-tubes, heating large volumes of liquids, handling glassware containing hot liquids, carrying glassware, handling of reagent bottles. Diluting concentrated acids and inserting glass tubing or thermometers in rubber stoppers should be done by the teacher in the preparation room before the experiment.
3.2.5 Biological hazards and use of live animals
Biology experiments have special ethical and practical problems.
See 2.0: Microbiology safety
1. Students and the local community may be upset if they think animals suffer during experiments, e.g. fish and frogs.
2. Human saliva, human cheek cells, human whole blood from a hospital source, and human teeth scrapings may transmit diseases. The use of body fluids for secondary school experiments is not favoured nowadays so many laboratory experiments are now being done with artificial solutions. Do not take blood samples from staff or students.
3. Studies of living mosquitoes may risk transmission of malaria and other diseases.
4. Most animals can inflict bites so handle them with great care. Animal bites may transmit infections and animals may carry human parasites.
5. Treat dissection material as if it is contaminated. Dissecting instruments must be sterilized before use.
6. Vermin and the insects are attracted to animal food. Mouldy and decaying animal food and animal wastes may be health hazards because of the presence of bacteria and other micro-organisms.
7. The teacher must answer the following questions about using live animals:
7.1 Is it essential for live animals to be kept?
7.2 Have alternatives to animal experiments been investigated?
7.3 Has the number of animals been kept to a minimum?
7.4 Will the animals be housed under appropriate conditions?
7.5 Who will take responsibility for feeding and caring for animals during holiday periods?
7.6 Have procedures been established for the safe handling of animals to reduce the risk to staff and students of being bitten or scratched?
3.3.1 Test-tubes, glassware and microscope slides
1. Never look down a test-tube and never point the open end of a test-tube at a student while a reaction occurs. Hold the test-tube up to the light and look from the side. Put the test-tube in a test-tube rack before putting chemicals in it. When heating substances in test-tubes, move the test-tube back and forth across the flame. Heat substances in wide test-tubes or boiling tubes.
2. When transferring materials from one container to another, hold the containers at arms length. Check glassware for cracks before use. Put broken glass metal pieces and unused chemicals in a specially marked container and bury them.
3. Microscope slides and coverslips are easily broken. Do not leave broken pieces on the desk. After each class where microscopes are used, wipe the benches with a damp cloth to remove broken glass, especially broken coverslips.
3.3.2 Fume cupboards, fume chambers, fume hoods
See diagram 1.13a: Simple fume hood
1. Do not use fume cupboards for long-term storage of any chemicals or as distribution areas for class sets of chemicals and equipment.
2. Most fume cupboards have an extraction fan mounted in the flue that conducts exhaust gases and vapours to the atmosphere. Check the extraction fan regularly. Heat-induced convection types of fume cupboards have a gas burner at the entrance to the flue to cause a rising convection current. However, these units may be fire hazards if flammable gases or liquids are placed in the fume cupboard.
3.3.3 Eye washing and safety showers
Doors in and around preparation rooms are usually locked for security reasons. However, to enable access to safety shower and eye washing facilities, ensure that connecting doors to preparation rooms are unlocked and open at the beginning of science classes. The first 30 seconds are critical in the treatment of chemical splashes in the eye. The minimum recommended time for continuation of eye washing is 20 minutes. Remove contact lenses. For permanent eye washing fixtures, the water stream should allow continual irrigation of the eye without harmful pressure being placed on it. You can squeeze an eyewash bottle to irrigate the eye for a short period but a continuous supply of water may still be needed when the eyewash bottle becomes empty. Regularly empty and refill eyewash bottles to prevent contamination by algae and micro-organisms. Wearing safety glasses lessens the possibility of eye injury.
Check the water pressure of safety showers or the nearest tap or hose. Where safety showers are installed, the person affected by a chemical spill should stand in the appropriate place and be thoroughly doused. Where safety showers are not installed, use the nearest tap or hose. Check periodically the permanent eye washing and safety shower facilities. Also, check the water pressure of safety showers or the nearest tap or hose.
3.3.5 Carbon dioxide soda syphon bulbs
Do not use CO2 (carbon dioxide) soda syphon bulbs in science teaching activities, e.g. demonstration of rocketry. Use of these bulbs has resulted in serious accidents. For example, in a recent report, a student stole a carbon dioxide cylinder from a school laboratory, threw it into a fire at home and was killed by the resulting explosion.
3.3.6 Glass wool
Students should not handle glass wool. Thin pieces of glass wool can get into cuts and then into the blood stream. Do not touch glass wool with the fingers and do not breathe it in. Teacher and laboratory assistant may use glass wool in the preparation room but they should wear an appropriate respiratory mask.
3.4.1 Correct names of chemicals
Usually, the chemical name used in this document is the standard name followed by synonyms. These names were checked with names in the document "Education Queensland (Australia), Aspects of Science management: A reference manual for Schools" 1997 and the catalogue of Philip Harris, UK.
3.4.2 Quantity of chemical to be used in experiments
1. In this document, "dilute solution" refers to a 2 M solution, or a 10% solution, unless otherwise specified.
2. In this document, "concentrated acid", or any other substance, refers to the concentration supplied by commercial suppliers, e.g. concentrated hydrochloric acid is 36% w / w, unless otherwise specified.
3. For all experiments, unless otherwise instructed, use either:
3.1 a 5 mL of solution, or
3.2 a test-tube filled to the depth of a finger width, or
3.3 the powder on a little finger nail, or
3.4 a piece of solid chemical the size of half a dried pea, or
3.5 no more than one third of a test-tube of any solution.
4. Do not make gas jars full of gas for demonstration purposes. Use test-tubes with stoppers to collect gases.
3.4.3 Prepare dilute acids and bases
1. Prepare dilute acids by slowly adding ACID TO WATER.
2. Keep concentrated mineral acids, e.g. hydrochloric sulfuric or nitric acids, in a special container on the floor of a locked cupboard. Only the teacher or a laboratory assistant may handle concentrated acids or strong bases.
3. Wear safety glasses to protect the eyes when handling concentrated acids. Students may handle dilute mineral acids and bases, but if they spill them on the skin or in the eyes, wash immediately with plenty of water.
4. Organic acids are not so dangerous as mineral acids, but phenol (carbolic acid) and ethanedioic acid-2-water (oxalic acid) are toxic.
5. Strong bases, e.g. sodium hydroxide (caustic soda) and potassium hydroxide (caustic potash) can cause burns. Weaker bases, e.g. calcium hydroxide (limewater, slaked lime) can cause burns if they are left in contact with the skin.
3.4.4 Corrosive substances
1. Corrosive substances are those that cause severe skin damage. How corrosive a substance is depends on the length of time taken for the damage to occur.
2. Splashes to the eyes present a far greater risk of severe injury than splashes to skin.
3. Indicators of corrosiveness
3.1 Highly corrosive substances cause visible severe skin damage at the site of contact in less than 3 minutes.
3.2 Corrosive substances cause visible severe skin damage at the site of contact in a period of 3 to 60 minutes.
3.3 Irritating substances cause visible severe skin damage at the site of contact in a period of up to four hours.
3.4.5 Skin contamination
1. The following sequence of procedures should be observed for skin contamination by substances other than phenolics: Remove contaminated clothing and simultaneously irrigate thoroughly the affected area with water. Continue drenching for five minutes and then wash gently with a little soap and a lot of water. Irrigate again with water and cover the affected area with gauze or lint.
2. The following sequence of procedures should be observed for skin contamination by phenolic substances: Swab off the phenol using swabs soaked in glycerine or vegetable oil. Discard each swab and continue with a new swab. Care must be taken to avoid spreading the burn.
3.4.6 Gas or vapour inhalation, EAR, CPR
The following sequence of procedures should be observed for the inhalation of a poisonous substance, e.g. a gas:
1. Carry or drag the patient into fresh air. Loosen clothing, check breathing, pulse and pupils of the eyes. If the patient is not breathing, pulse is absent and eyes are dilated, start Expired Air Resuscitation (EAR) / Cardio-Pulmonary Resuscitation (CPR).
2. If patient is not breathing, but pulse is present, start Expired Air Resuscitation (EAR).
3. If patient is breathing but unconscious, place patient flat on the floor, roll him / her onto right side, remove dentures and clean mouth of mucus and vomitus. Keep the patient's chin well up and forward by pushing on the angle of the jaw. Keep the patient warm. Do not give anything by mouth to the unconscious patient. If conscious, encourage the patient to take a series of rapid and deep breaths, then gradually bring him / her into a sitting position. Make certain the patient does not get up and walk around. Make the patient lie flat if he or she feels faint.
4. If the heart has stopped beating, CPR can restore blood flow and ventilation. The compression to the rib cage over the sternum reduces the volume of the thoracic cavity, squeezes the heart and pushes blood into the aorta and pulmonary trunk. With removal of the pressure, the thorax expands and blood moves into the main veins. The cycles of compression must be interspersed with cycles of mouth-to-mouth breathing that maintain pulmonary ventilation. It is difficult to practise CPR on a living person without causing injury,
e.g. broken ribs.
3.4.7 Chemicals swallowed
The following sequence of procedures should be observed after ingestion of a poisonous substance.
Treatment for an unconscious patient
1. Do not give anything by mouth. Place patient flat on back and then roll him / her onto the side. Put your finger in the patient's mouth and remove dentures and any obstructions to breathing. Hold the patient's jaw well up and forward.
2. Check breathing. If not breathing, turn casualty on to back and apply E.A.R.
3. Check pulse. If pulse absent, apply C.P.R. Loosen clothing around neck, abdomen and chest.
4. If the patient vomits, clean out his / her mouth. Arrange transport to hospital or doctor.
Treatment for a conscious patient
1. If the substance swallowed can be identified as: a strong acid, a strong alkali or other corrosive, a phenolic substance, kerosene or a petroleum product, or is listed under poisons FIRST AID list (which should be displayed in an appropriate location) as a substance for which vomiting should not be induced, then do not induce vomiting but follow the first aid instructions.
2. Give fluids, water or milk only if indicated in the poisons FIRST AID list for the specific poison. Do not give more than 250 mL as this may induce vomiting.
3. If vomiting is to be induced, use syrup of ipecac. Do not give milk as this increases the risks if aspirated. If advised by a doctor, or Poisons Information Centre, or if not contradicted above, induce vomiting by the appropriate dose of syrup of ipecac: 30 mL for adult, 15 mL for children, followed by 200 mL of water. If vomiting has not occurred in 30 minutes, the ipecac syrup may be repeated once only.
4. If in doubt about the identity of the poison, do not induce vomiting. Keep patient warm, comfortable and calm while waiting and being transported to hospital.
3.4.8 Chemical vapours and smelling chemicals
See diagram 1.13: Smelling chemicals
1. Isolate chemical vapours by doing experiments in a fume cupboard or use very small quantities of chemicals near an open window with good ventilation.
2. Do not inhale gases directly from the test-tube. Fill the lungs by breathing in deeply. Close the mouth then fan the gas towards the nose with the hand and sniff cautiously. If you detect no odour, move closer and try again. When you detect the odour breathe out through the nose again.
3.4.9 Tasting chemicals
Never taste a chemical or any substance in the laboratory except for a few experiments where you are specifically told to taste the chemical.
3.4.10 Handling and transferring chemicals
1. Do not touch any chemical or any substance in the laboratory except for a few experiments where you are told to feel the texture of chemicals or minerals to determine whether they are crystalline or amorphous. If you do touch any chemical, immediately wash the hands with soap and water.
2. Always use a spatula or gloves to move or touch chemicals.
3. The best way to add chemical to a container is to pour the powdered or crystalline chemical into a creased rectangle of clean paper then tip the chemical from this paper held in a V- shape.
4. When taking chemicals from a container, after removing the stopper, keep holding the stopper in one hand so that you can replace it immediately afterwards. This method ensures that the chemical does not have unnecessary exposure to air and that the correct stopper is replaced.
5. Transfer liquids through a funnel or pour the liquid slowly down a glass rod.
6. Fill pipettes with a pipette-filler and not by sucking by mouth.
3.4.11 Disposal of waste chemicals
1.0 Do not keep any chemicals that do not have labels or are not on a list of chemicals approved by the Ministry of Education. Ask officials in the Ministry of Education chemists or chemists in a government chemistry laboratory how to dispose of these unwanted chemicals.
1.1 Avoid waste by using chemicals only in those quantities necessary for the learning experience.
1.2 Avoid using the more expensive chemicals, e.g. silver chloride.
1.2 Re-use chemicals not affected by the chemical process, e.g. metals and metal carbonates + acids usually leave residues of unaffected metal and carbonate that may be washed clean and reused.
1.3 Recycle chemicals produced by chemical processes, but only when the process of recycling is simple and not hazardous. For example, recrystallize copper sulfate crystals from solutions by evaporation or by placing steel wool in the solution overnight, but do not recycle lead or mercury salts.
1.4 Do not burn unwanted chemicals because they may form carcinogenic gases.
2.0 Methods of disposal may include the following:
2.1 Wash down the sink
2.1.1 Waste solutions of most chemicals used in school science experiments may be disposed of down the sink to the sewer. In some countries the effluent must comply with specific limits for disposal of chemicals to the sewer, e.g. ammonia, limit of 40 grams / day or 29 L of 0.1 M soln /day.
2.1.2 Dilute wastes miscible with water or already in solution with a large volume of water, then neutralize with sodium carbonate or dilute hydrochloric acid, then wash down the sink, e.g. salt solutions, ethanol
2.1.3 Treat heavy metal wastes with sodium hydroxide until pH 8-10, then wash down the sink..
2.2 Dispose with normal refuse.
2.2.1 Wrap solid wastes in paper and place in the garbage, e.g. iron filings
2.2.2 Absorb wastes not miscible with water onto paper or vermiculite or perlite or cat litter, then seal in a plastic bag and place in the garbage.
2.3 Add water or strong alkali and let evaporate in a fume cupboard.
2.4 Waste bottles can be used to store heavy metal wastes and other waste chemicals, to be later taken away by a waste contractor.
2.5 Deliver to a government chemistry laboratory
3.1 Hydrogen sulfide warning
Do not add acidified solutions to metal sulfides because the reaction produces hydrogen sulfide gas. If a rotten egg smell indicates production of hydrogen sulfide gas in a waste bottle, add solid sodium hydroxide until the solution pH >7 and leave in fume cupboard with lid off until no smell occurs.
3.2 Copper residues
Copper residues can be used to demonstrate recovery of the metal by displacement from solution by a more active metal, e.g. scrap iron or steel wool. precipitate insoluble copper or zinc sulfide by adding sodium sulfide solution, filter off the insoluble sulfide, dry and dispose of as solid waste. Copper residues can be treated to recover copper sulfate by evaporation. If disposal is intended, copper residues can be treated with iron to reduce copper ions to metallic copper. Place copper residues in a large container and add sufficient steel wool to achieve discoloration of the blue solution. Pour off the iron solution. Wrap the solid reduced copper in newspaper and dispose in your solid waste bin. Flush the iron solution with water to the sink or pour over the ground or school garden. Recover iron salts by evaporation and late dispose in a solid waste bin.
3.3 Lead residues
Lead residues may contain metallic lead, solid lead salts and lead ions in solution. Do not recycle lead in the school laboratory but dispose them through a licensed waste contractor or government chemistry laboratory.
3.4 Mercury residues
Mercury residues must be kept well-sealed, especially if mercury residues mercury metal is present. Do not clean waste mercury in the school laboratory but store for removal by a licensed waste contractor or government chemistry laboratory.
3.5 Organic liquid residues
Keep halogenated and non-halogenated organic liquid residues separate. Use the bottles for immiscible liquids only. Keep them away from ignition sources and store them in a fume cupboard for removal by a licensed waste contractor or government chemistry laboratory.
3.6 Silver residues
Add solid sodium chloride to precipitate the silver as silver chloride. Decant the clear solution and wash down the sink. Store the precipitate for recycling or waste collection or give to a commercial photographer. To recover silver, add sodium carbonate to waste fixer to form a silver carbonate precipitate, then collect and dry the precipitate. Heat the precipitate with carbon powder or on a carbon block to form metallic silver. Most metals will displace silver metal from soluble silver salt solutions to form attractive silver crystals. Observe too small to see silver particles in solution form a growing crystal.
3.7 Zinc residues
Treat for recycling or dispose to garbage. Precipitate insoluble zinc sulfide by adding sodium sulfide solution, filter off the insoluble sulfide, dry and dispose of as solid waste.
3.4.12 Chemicals spill kit
After a spill, open windows and doors to improve cross-ventilation, and immediately inform school authorities.
1. A school science laboratory spill kit could contain the following items:
Cardboard box
Disposable rubber gloves
Dust pan and bucket
Mop and bucket
Nitrite rubber gloves
Paper towel
Plastic bucket, 5L
Plastic scoop
Respirator, with P2 cartridge
Safety glasses and safety goggles
Sodium bicarbonate, sodium hydrogen carbonate, 2 kg
Sodium carbonate, 2 kg
Sulfur, 2 kg, for mercury decontamination
Vermiculite or perlite or cat litter, 5 kg
2. Commercial spill kit, colour-coded to ensure rapid identification, contains absorbent pads, spill containment booms, sukerup 100% organic general purpose absorbent, personal protection equipment, contaminated waste bags and ties, adhesive wall locator, laminated instruction sheets, 20 litre kit, 32 litre kit
1.0. Store acids
Store concentrated acids in plastic boxes on the floor. Store acetic acid (ethanoic acid) away from other acids, preferably in another room. Store concentrated sodium hydroxide in plastic boxes on the floor but away from the acids. Do not use glass stoppers. Store formalin, solution of formaldehyde (methanal) in water, in glass bottles away from hydrochloric acid.
2.0. Store alkalis
Store alkalis at floor level standing in a strong plastic tray large enough to contain the volume of the container if breakage or spill occurs. Store concentrate alkalis away from concentrated acids and apart from metals. Store ammonia solution (10% ammonia solution) as with acids but separate from them, not near oxidizing agents. Ammonia solution produces dangerous irritating ammonia fumes. Carefully unstopper bottles of ammonia solution in a fume cupboard to prevent damage to the eyes from the fumes. Dilute ammonia solution by adding ammonia solution to water in a fume cupboard.
3.0. Store chromium (VI) oxide
Chromium (VI) oxide may cause fire on contact with combustible materials. Contact with skin causes severe burns. Spread soda ash over spillage and use plenty of water.
4.0. Store flammable liquids
Store flammable liquids at eye level in a well-ventilated area away from heat sources. Flammable liquids may include methylated spirit, nail polish remover (acetone), cleaning products, paints and glues. Store strong oxidants away from flammable organic chemicals.
5.0. Store hygroscopic substances
Hygroscopic substances absorb water from the air, e.g. concentrated sodium hydroxide and potassium hydroxide, concentrated sulfuric acid, glycerine and ethanol ("absolute alcohol"). Deliquescent substances are hygroscopic substances that absorb water to such an extent that they form a concentrated solution of the substance, e.g. calcium chloride. Both hygroscopic and deliquescent substances may absorb moisture from tissue so treat them as potentially highly corrosive.
6.0. Store organic chemicals
Store organic chemicals inside self-sealing plastic bags. This eliminates the smell associated with such chemicals it also gives early warning of any leaking bottle.
7.0. Store oxidizing agents
Powerful oxidizing agents, e.g. chlorates, peroxides, perchlorates, and perchloric acid, are not usually found in school science laboratories. Store them in a desiccator away from other chemicals. Oxidizing materials are chemicals that support combustion or burning. If they are placed in contact with materials that act as fuels, there is danger of an explosion or fire. Oxidizing materials include chlorates, peroxides, perchlorates, and perchloric acid.
8.0. Store reagent bottles and stock bottles
Reagent solutions and solids must be constantly checked and replaced where necessary from stock bottles. The reagent bottles should be labelled with the name of the substance and the concentration of the solution. Unused reagents should never be returned to the stock bottles.
9.0. Store sodium and potassium
Sodium and potassium react violently with water, and the heat produced can ignite the hydrogen gas evolved. Contact with skin causes thermal and caustic burns. Cutting heavily oxidized potassium may cause an explosion because of the combination of the dioxide with organic material. Dispose of old stocks of potassium by dissolving the uncut lumps in propan-2-ol.
10.0. Store sodium chlorate and potassium chlorate
Store sodium chlorate and potassium chlorate away from strong acids and any substances that are easily oxidized, e.g. sulfur, sulfides, phosphorus, sucrose (cane sugar) alcohols, organic solvents, ammonium compounds, powdered metals, oils or grease, and dust.
3.5.1 Action in case of fire - evacuation
If a fire should break out in an area for the teaching of science, the students must be moved from the source of the fire and evacuated, if necessary. A whole school evacuation may be necessary. Observe the school's evacuation procedures, including contact with the fire brigade. The school's procedures must have additional instructions for everyone in workshop areas, including science areas. Besides the school fire drill, science classes should practice a special fire drill for the laboratory.
3.5.2 Action in case of fire - equipment
1. All participants in any science activity must know the location and mode of operation of fire extinguishers, fire blankets and sand buckets.
2. Check fire extinguishers regularly to make sure they are in working condition. Check them for leakage, tampering and expiration of "use by" dates. Check that students have not tampered with gas fittings.
3. Store fire extinguishers on the floor near the front door of the laboratory. Keep a fire blanket near the fire extinguishers. Dry chemical fire extinguishers can be used on all types of fires but follow the manufacturer's instructions on the device.
4. During a science class a school laboratory should have two unlocked doors, preferably at each end of the laboratory.
Commercial
Fire blanket, Chubb, fibreglass, 1800 mm × 1200 mm
Fire extinguisher, Chubb, dry chemical powder, A:B(E) suitable for fighting class A, B, C and E fires,
paper, wood, textile, oil, liquid, and electrical fires, 2.5 kg with wall bracket
3.5.3 Electrical fires
Do not connect appliances or equipment whose current rating is greater than that of the power outlet. General purpose outlets (GPOs) were usually rated at 10 amps. Some GPOs may be rated at 15 amps. Do not use double adapters. Instead use portable power boards (multiple point power boards), especially those with circuit breakers. Make sure that all power leads are in good condition with no breaks or frays in the insulation, are of the appropriate current rating for the appliance being used, and are
of the minimum length necessary for use.
3.5.4 Fire prevention - possible sources of ignition
1. Fires in school areas for the teaching of science may arise from chemical reactions, electrical faults, gas leakage and poor laboratory procedures. The speed with which the fire can spread will depend on the nature of the burning substances and the materials close to the fire. Fires of solids propagate slowly. Fires of liquids spread less rapidly. Gas, vapour or dust fires propagate so rapidly that they seem to explode. Propellant gases in aerosol cans may be flammable, so avoid using aerosol cans near flames.
Fluorescent lights and electrical switches may emit sparks. Use very small quantities of substances to be burnt in oxygen.
2. Extinguish matches completely after use and place them in a non-flammable container, not in a waste receptacle. Use friction or piezoelectric lighters instead of matches.
3. Leave lighted Bunsen burners with the air hole closed to make the flame visible.
4. Place hot objects on a cool gauze mat or other heat proof mat, not on bench tops, paper or other flammable substances. Allow apparatus used during heating to cool before storage. Keep attending to hot plates, radiators and other sources of high heat. Do not leave them switched on overnight.
5. Do not leave sodium and phosphorus exposed to the air.
6. Keep paper, hair and flammable clothing away from flames during experiments.
7. All personnel involved in science activities must know the position of the isolating valve for the room and the isolating valve at the bottled gas cylinders or gas meter.
3.5.5 Clothes on fire
If a student's clothes have caught fire, lay the student down, roll them over and smother the flames with the fire blanket. For any burns, dowse the burn area with clean cold water and seek urgent medical attention.
3.5.6 Burning fat in a frying pan
Immediately turn off the source of heat and cover the frying pan with a plate, flat object or fire blanket to smother the flames, i.e. deprive the flames of oxygen gas. Do not throw the fire blanket over a cooking fat fire but place it over the frying pan carefully while keeping the hands and face protected behind it. Turn off the heat sources and leave the fire blanket in place for 15 minutes to allow the heat to dissipate. Do not allow water to enter the burning fat in the frying pan, even from wet hands, because the water will vaporize immediately and spread the hot burning fat.
3.5.7 Flammable substances
See 15.7.0: Flammable organic chemicals
See 15.8.0: Flammable organic chemicals with low flashpoint below 32oC
1. Flammability is the tendency of a material to ignite and continue to burn. Most polymers are flammable because they contain carbon and hydrogen and have large heats of combustion. In general speech, inflammable substances are likely to catch fire, they are readily ignited.
2. Degrees of flammability
2.1 Highly flammable substances have a very low boiling point, form vapours easily at room temperature and are easily ignited, e.g. petrol.
2.2 Flammable substances have a higher boiling point, form vapours less easily and require a higher temperature for ignition, e.g. diesel.
2.3 Combustible substances do not form vapours easily at room temperature and require a much higher temperature for ignition, e. g. paper.
3.5.8 Flammable liquids
Do not use any sources of ignition near flammable liquids. Low flash point substances ignite very easily and may form an explosive vapour air mixture. The following flammable liquids are allowed, if the precautions in this document are followed: ethanol, ethyl acetate, n-hexane, methylated spirit, formaldehyde solution. The following common flammable liquids are sometimes found in a school chemistry laboratory but should not be used in school experiments: benzene (benzol is crude benzene motor spirit) butan-1-ol, butan-2-ol, carbon disulfide CS2, diethyl ether (C2H5)2O, cyclohexane, iso-octane, n-octane, methanol, petroleum spirit, propanol, propan-2-ol, toluene.
3.5.9 Flammable gases
Extinguish all sources of ignition when handling flammable gases. Turn off any Bunsen burners or, better still, use electrical hot plates. For demonstrations of ignition tests of gases use only small quantities of gas. The source of gas should be closed off or be far from the demonstration. Similarly, for demonstrations of combustion of substances in an oxygen gas rich environment, use only small quantities of substance because the substance may flare and burn rapidly. Many propellant gases in pressure cans are flammable. Do not use carbon dioxide cylinders as a source of propellant gases. Some fluorescent lights, electrical switches and transmitting devices (radios and mobile telephones) may be sources of ignition.
3.5.10 Combustible solids
Most combustible solids are not a fire hazard unless ground into a powder. Powders of combustible solids can be explosive when dispersed in the air. Metals in a finely divided form may ignite easily, e.g. zinc dust. Unstable solids may decompose explosively if heated or subjected to friction, e.g. potassium chlorate, sodium nitrate, potassium nitrate, ammonium nitrate, powdered metals and
powdered sulfur. Strong oxidizing agents in contact with organic substances may lead to spontaneous ignition. Solids that can react spontaneously and exothermically with water or air include lithium, sodium, potassium, calcium, hydrides, nitrides, sulfides, acid anhydrides and concentrated acids and alkalis. Use only small quantities of these chemicals. Never keep them in small narrow neck containers. Some solids may react with water or air giving off great heat, e.g. lithium, sodium, potassium, calcium, hydrides, nitrides, sulfides, acid anhydrides, concentrated acids and concentrated alkalis, so use only very small quantities and do not keep them in small narrow neck containers. Spontaneous ignition may occur between strong oxidizing agents and organic chemicals so do not store
them together.
3.5.11 Fireproof cloth
1. Fireproof with ammonium chloride solution. Soak cloth in the solution and let it dry. Hold the cloth over a flame. The cloth will only smoulder. When the flame is removed, the burning stops. Fabrics are often treated this way to prepare them fireproof.
2. Fireproof paper with alum. Soak half a piece of paper or cloth in an alum solution, potash alum Al2(SO4)3.K2(SO4).24H2O, (also shown as KAl(SO4)2.12H2O). Set fire to the untreated half and observe the flames when they reach the treated half. Alum acts as a flame retardant. It forms a buffer between a flammable substance and a source of ignition, being incombustible with its many molecules of water that it can lose at 200oC
3. Fireproof wood with sodium silicate solution. Hold a match by the head and dip it into a mixture of 1 part sodium silicate solution and 3 parts water. Let the match dry completely. Light the match. The wood burns, but when the flame reaches the coating of sodium silicate, it is extinguished.
4. Fireproof with sodium thiosulfate, (hypo). Soak 2 wooden matches in a concentrated solution of sodium thiosulfate for 2 hours. Strike the matches and see whether the wood will burn
3.6.0 Toxicity of metals and metal compounds
Toxicity is the capacity of a substance to cause harm. All chemicals should be considered as partially toxic. The toxicity of a substance is determined by the quantity of that substance required to cause harm. Risks of injury associated with any particular chemical relate directly to the route of entry, i.e. ingestion, inhalation or skin contact. A substance that may be very toxic by ingestion may be quite safe to handle if it is not ingested. Toxicity is usually reported as an LD50 oral rate, i.e. the lethal dose that will kill 50% of a sample rat population if administered orally. The following values are approximate indicators for ingestion: very toxic: LD50 < 25 mg / kg body weight, toxic: LD50 < 200 mg / kg body weight, harmful: LD50 < 2000 mg / kg body weight.
The following chemicals are poisons and should never be used in a school laboratory:
carbon tetrachloride (CCl4, tetrachloromethane)
carbon disulfide (CS2)
chloroform (CCl3)
mercury (Hg, mercury metal)
mercury (II) oxide (HgO,
red mercuric oxide) all mercury salts,
phenol (C6H5OH, carbolic acid)
phosphorus, P (white phosphorus, yellow phosphorus).
3.6.1 Aluminium, toxicity
The metal aluminium itself is not generally regarded as a poison. The toxicity of any compound will be determined by the nature of the anion with which the metal is combined. Alum, potassium alum, has the formula: Al2(SO4)3.K2(SO4).24H2O
3.6.2 Barium, toxicity
The soluble barium salts such as the chloride and sulfide are poisonous when taken by mouth. The insoluble sulfate used in radiography is non-poisonous. The usual result of exposure to the sulfide, oxide and carbonate is irritation of the eyes, nose and throat and of the skin.
3.6.3 Boron, toxicity
Although boron itself is not highly toxic, instances of accidental poisoning have been reported because of boric acid (boracic acid) oral ingestion of borates and absorption of boric acid from wounds and burns.
3.6.4 Calcium, toxicity
Compounds of calcium should be considered toxic only when they contain a toxic component. Calcium oxide and calcium hydroxide have caustic reactions and are therefore irritating to the skin and respiratory system.
3.6.5 Chromium, toxicity
Chromic acid and its salts have a highly corrosive action on the skin and mucous membrane. Chromate salts are recognized carcinogens. The red, orange and yellow pigments of chromium contain the highly toxic carcinogenic Cr(VI) and are not permitted in schools. The green pigments of chromium contain the less toxic Cr(III), e.g. lead chromate, (yellow 34), chromium (III) oxide (green 17).
3.6.6 Cobalt, toxicity
The toxicity of cobalt itself and most cobalt salts is low. The toxicity of the compound will depend upon the anion with which cobalt is combined
3.6.7 Copper, toxicity
The salts copper chloride and copper (II) sulfate have been reported as causing irritation of the skin and conjunctivas. Copper oxide is irritating to the eyes and upper respiratory tract. The ingestion of large amounts of copper (II) sulfate can have fatal effects.
3.6.8 Lead, toxicity
Cases of lead poisoning may occur: 1. by inhalation of dusts, fumes, mists or vapours 2. by ingestion of lead compounds introduced into the mouth on food, tobacco, fingers, and (c) through the skin, particularly in the case of organic lead compounds. Lead is a cumulative poison. Increasing amounts build up in the body and eventually a point is reached where symptoms and disability occur. Of the various compounds, the carbonate, the monoxide and the sulfate are considered to be more toxic than metallic lead or other lead compounds.
3.6.9 Magnesium, toxicity
Poisoning can result from prolonged exposure to fumes or dusts.
3.6.10 Mercury, toxicity
DO NOT USE MERCURY IN SCHOOL SCIENCE EXPERIMENTS
DO NOT STORE MERCURY IN THE SCHOOL LABORATORY
1. A number of mercury compounds can cause skin irritation and can be absorbed through the skin leading to mercury poisoning. Mercury compounds and the metal itself may enter the body as vapours of fumes or dusts. Some can cause kidney damage while others can cause irreversible damage to the central nervous system. Mercuric compounds are generally more toxic than mercurous compounds. Give any mercury stored in the laboratory to a government laboratory.
2. Mercury vapour is Toxic and may damage the nervous system. Mercury enters the body by inhalation, ingestion or through the skin. Mercury vaporizes at the temperature at which water freezes. The vapour is odourless, tasteless, and colourless. Chronic exposure may result in cumulative poisoning with nervous and psychic symptoms.
1. Students may observe mercury in a mercury glass thermometer, but the teacher must keep hold of the thermometer and not leave it on the bench where it may roll off and break on the floor. If mercury spills from a broken thermometer, immediately remove the students from the room and open the windows. Close doors opening into corridors. Pick up all the mercury with a damp cloth or a water suction pump. Sprinkle zinc powder or sulfur powder or agricultural spray that contains sulfur over the area of the spillage. These substances react with mercury to form an inert material that does not vaporize. Collect the mercury and zinc or sulfur with a wet cloth or use a dustpan and broom to gather the mercury into one small mass. Put the mercury in a plastic container that can be sealed tightly. Give the mercury recovered to a government laboratory. Contamination by many small globules left in cracks and crevices is possible after most mercury has been removed. Keep zinc dust or powdered sulfur handy in the laboratory. Report any mercury spillage to the principal who may ask health authorities for advice on any further safety action.
3.6.11 Nickel, toxicity
Although nickel and most salts of nickel are generally not considered toxic, nickel (II) compounds are carcinogenic.
3.6.12 Potassium, toxicity
Toxicity of the compounds is variable. The potassium ion is practically non-toxic, hence the toxicity of potassium compounds would depend upon the anion involved.
3.6.13 Silver, toxicity
The silver ion is intensely corrosive to tissue.
3.6.14 Sodium, toxicity
Toxicity of sodium varies with the compound. The sodium ion is considered non-toxic. The toxicity of sodium compounds is frequently, though not always, because of the anion involved.
3.6.15 Strontium, toxicity
The strontium ion has a low order of toxicity. It is chemically and biologically similar to calcium. The toxicity of the compounds is considered to be dependent upon the anion involved.
3.6.16 Zinc, toxicity
Although zinc is not inherently a toxic element, small doses of soluble zinc salts cause nausea and vomiting. Larger doses cause violent vomiting and purging. Zinc chloride, because of its caustic action, can produce skin ulcers.
3.7.1 Bromides, hazards
1. The inorganic bromides produce depression, emaciation and in severe cases psychoses and mental deterioration. (Bromides were formerly used as sedatives, to control unruly children and, it is still commonly alleged that potassium bromide was added to tea to control the sexual feelings of soldiers in barracks.)
2. Organic bromides are volatile liquids of relatively high toxicity. When strongly heated, alone or with concentrated sulfuric acid, they emit highly toxic fumes.
3.7.2 Chlorates, hazards, potassium chlorate
1. The principal toxic effect of chlorates is the destruction of the red blood cells, leading to kidney irritation.
2. Chlorates constitute a dangerous fire hazard in contact with flammable materials. So solid chlorates should never be placed in rubbish bins. Chlorates are powerful oxidizing agents and when contaminated with material that can be oxidized they are particularly sensitive to friction, heat and shock.
1. When mixed with combustible material chlorates can form explosive mixtures. The reaction with concentrated sulfuric acid can be violent.
4. Do not prepare oxygen gas with potassium chlorate and manganese dioxide as a catalyst because this mixture may explode! The recommended method for preparing oxygen gas is to heat 20 vols hydrogen peroxide solution.
3.7.3 Chlorides, hazards
Toxicity varies widely. When heated strongly, alone or with concentrated sulfuric acid, they can emit highly toxic fumes.
3.7.4 Chromates, dichromates, hazards
These compounds have a corrosive action on skin and mucous membranes. Because they are strong oxidizing agents, they could cause fire by a chemical reaction. Hexavalent chromium compounds are known to be carcinogenic.
3.7.5 Ferricyanides, hazards
The ferricyanides as such are of low toxicity since the CN is bound. However, when strongly heated or on contact with acids or acid fumes, highly toxic fumes are liberated.
3.7.6 Ferrocyanides, hazards
Ferrocyanides as such are of low order of toxicity but highly toxic decomposition products can form on mixing them with hot concentrated acids. When strongly heated they emit highly toxic fumes.
3.7.7 Hypochlorites, hazards
These compounds are corrosive. When heated or on contact with acids or acid fumes they emit highly toxic fumes. They form a moderate fire hazard by chemical reaction with reducing agents and organic matter.
3.7.8 Iodates, hazards
Toxicity is variable, producing effects similar to those produced by chlorates. They are a dangerous fire hazard because they are powerful oxidizers. In contact with flammable or even combustible materials they can start fires.
3.7.9 Iodides, hazards, iodine allergy
Similar in toxicity to bromides. When strongly heated they emit highly toxic fumes.
An iodine allergy is very rare and is usually confused with an allergy to shellfish or fish, a rich source of iodine. However, only about 5% of people allergic to shellfish show symptoms of iodine allergy. An iodine allergy could be a response to iodine medicine on the skin or iodine injected for X-ray contrast and could result in anaphylactic shock. An injection of epinephrine may be necessary to stop the histamine reaction. Also, people with impaired kidney function may not be able to eliminate iodine.
3.7.10 Nitrates, hazards
Large amounts taken by mouth may have serious or even fatal effects. Practically all nitrates are powerful oxidizing agents and, as such, constitute a moderate fire hazard by chemical reaction. Nitrates may explode when exposed to heat or flame or by spontaneous chemical reaction. Ammonium nitrate has all the properties of the other nitrates but is also able to detonate by itself. On strong heating, nitrates emit toxic fumes.
3.7.11 Oxalates, hazards
Oxalates are corrosive and produce local irritation. When taken by mouth they have a caustic effect on the mouth, oesophagus and stomach. The soluble oxalates are readily absorbed from the gastro-intestinal tract and can cause severe damage to the kidneys. When strongly heated they emit toxic fumes.
3.7.12 Permanganates, hazards
Highly toxic compounds with irritant properties. They are strong oxidizing agents and constitute a moderate fire hazard when reacting with reducing materials. Metallic permanganate may detonate when exposed to high temperatures or shock. The reaction with concentrated sulfuric acid can be violent.
3.7.13 Peroxides, hazards
Toxicity of these compounds is variable. They may cause injury on contact with skin or mucous membranes. They represent a moderate to dangerous fire hazard by chemical reaction with reducing agents and contaminants. They are strong oxidizing agents. Contact with water may cause violent decomposition.
3.7.14 Phosphates, hazards
Variable toxicity. When strongly heated they can emit highly toxic fumes.
3.7.15 Sulfates, hazards
Variable toxicity. In general, the toxic quality of substances containing the sulfate radical is that of the material with which this radical is combined. On strong heating, emits highly toxic fumes.
3.7.16 Sulfides, hazards
Variable toxicity. The sulfides of potassium, calcium, ammonium and sodium are similar in action to the alkalis. They cause softening and irritation of the skin. If taken by mouth they are corrosive. Sulfides of the heavy metals are generally insoluble and hence have little toxic action except through the liberation of hydrogen sulfide. They constitute a moderate fire hazard when exposed to flame or by spontaneous chemical reaction. Many sulfides ignite easily in air at room temperature. Others require a higher temperature or the presence of an oxidizer. Many powerful oxidizers on contact with sulfides ignite violently.
3.7.17 Sulfites, hazards
Fairly large doses of sulfites can be tolerated since they are rapidly oxidized to sulfates, although if swallowed they may cause irritation of the stomach by liberating sulfurous acid. When heated strongly or on contact with acids they emit highly toxic fumes.
3.7.18 Thiocyanates, hazards
Severe toxicity will occur with doses of less than 1 g. When strongly heated or on contact with acids or acid fumes, they emit highly toxic fumes.
3.7.19 Thiosulfates, hazards
Most of the thiosulfates have low toxicity. When heated strongly, they emit highly toxic fumes.
3.8.1 Ammonia, anhydrous, hazards
Extremely irritating gas. Flammable in the presence of sufficient oxygen gas. Do not prepare ammonia in an open room. Use fume cupboard.
3.8.2 Carbon dioxide, hazards
Simple asphyxiant.
3.8.3 Carbon monoxide, hazards
Very toxic. Can cause unconsciousness due to combination of the gas with haemoglobin in the blood. Death can occur from carbon monoxide inhalation. Do not prepare carbon monoxide in an open room.
3.8.4 Chlorine, hazards
Very toxic. Can react to cause fires or explosions upon contact with turpentine, ether, ammonia gas, illuminating gas, hydrocarbon, hydrogen gas and powdered metals. Dissolves readily in water forming highly corrosive solution. Do not prepare chlorine in open room. Use fume cupboard. Direct combination of chlorine and hydrogen gas in bright light or ignition of the mixture by lighted taper or electric spark. For the reactions of chlorine with metals, solid non-metals, hydrocarbons, use small quantities only.
3.8.5 Hydrogen gas, hazards
Do not allow direct combination of hydrogen gas and chlorine in bright light or ignition of the mixture by lighted taper or electric spark. Igniting a jet of hydrogen gas from a delivery tube. Reduction of metallic oxides by passing hydrogen gas over the heated oxide.
3.8.6 Hydrogen chloride, anhydrous, hazards
Corrosive. Do not prepare hydrogen chloride in open room. Use fume cupboard.
3.8.7 Hydrogen sulfide, hazards
Both an irritant and an asphyxiant. Do not prepare hydrogen sulfide in open room. Use fume cupboard. Igniting a jet of hydrogen sulfide issuing from a delivery tube.
3.8.8 LP gas (bottled gas), hazards
Simple asphyxiant. Consists of propane (approximately 95%) together with varying proportions of butane, propylene and butylene. A rank smelling compound is added so that the presence of the gas can be easily detected. Incomplete combustion forms carbon monoxide. Do not search for a gas leak with a lighted match or lighted taper. Use a soap solution.
3.8.9 Natural gas, hazards
Simple asphyxiant. Consists of methane (approximately 90%) together with varying proportions of ethane, propane, butane, nitrogen and carbon dioxide. A rank smelling compound is added so that the presence of the gas can be easily detected. Incomplete combustion forms carbon monoxide. Do not search for a gas leak with a lighted match or lighted taper. Use a soap solution.
3.9.3 Expired air resuscitation (EAR) and Cardiopulmonary resuscitation (CPR)
See 9.242.1: Expired air resuscitation (EAR), Adult
See 9.242.2: Expired air resuscitation (EAR), Infant (under 1 year), and Child (aged 1 to 8)
See 9.242.3: Cardiopulmonary resuscitation (CPR), Adult
See 9.242.4: Cardiopulmonary resuscitation (CPR), Child (aged 1-8 years)
See 9.242.5: Cardiopulmonary resuscitation (CPR), Infant (under 1 year)
3.10.0 Toxicity, Poisons and FIRST AID
Poison First aid if ingested
Acetic acid glacial Do not induce vomiting. Give 120-240 mL water or milk.
Acetone Give water. Induce vomiting, if large quantity > 20 mL.
Aceto-orcein stain Do not induce vomiting. Give water or milk.
Acridine Give water. Induce vomiting.
Adrenaline Give water.
Aluminium chloride Give milk or water.
Aluminium nitrate Give water. Induce vomiting.
Aluminium oxide Give 120-240 mL milk or water.
Ammonia concentrated Do not induce vomiting. Give 120-240 mL milk or water.
Ammonium dichromate Do not induce vomiting. Give 120-240 mL milk or water.
Ammonium metavanadate Give 120-240 mL milk or water
Ammonium molybdate Give 120-240 mL milk or water.
Ammonium oxalate Give milk or water. Give calcium as milk, weak limewater, chalk soln.
Ammonium persulfate Give 120-240 mL milk or water. Do not induce vomiting
Ammonium thiocyanate Give water. Induce vomiting.
Iso-amyl alcohol Give water. Induce vomiting if patient not drowsy.
Aniline sulfate Give water. Induce vomiting.
Barium compounds Give water, give magnesium sulfate,
(50 mg / kg for children to a maximum dose of 30 g adult).
Benedict's soln. Do not induce vomiting. Give 120-240 mL milk or water.
Bial's reagent, (orcinol in concentrated HCl) Do not induce vomiting. Give 120-240 mL milk or water.
Boric acid Give water. Induce vomiting.
Bromine liquid Give milk or water. Do not induce vomiting.
Buffer soln. tablets
pH 2 		Give milk or water. Give calcium as milk, weak limewater or chalk.
pH 4-10. Do not induce vomiting. Give 120-240 mL milk or water.
Butanol, primary, secondary and tertiary Give water. Induce vomiting if patient not drowsy.
Calcium acetate monohydrate Give milk or water. Do not induce vomiting.
Calcium hydroxide Give milk or water. Do not induce vomiting.
Calcium metal Remove any adhering metal and penetrating particles. Drench skin
with water except when contact has been slight. Rinse mouth
thoroughly with water. Give plenty of water.
Calcium oxide Do not induce vomiting. Give 120-240 mL milk or water.
Camphor Do not induce vomiting. Give 120-240 mL milk or water.
Carbon disulfide
 Give water. Induce vomiting. Give water.
Do not induce vomiting, may cause seizures.
Carbon tetrachloride Give water. Induce vomiting. Give water. Do not induce vomiting,
may cause seizures.
Chloroform Give water. Do not induce vomiting.
Chrome alum Do not induce vomiting. Give 120-240 mL milk or water.
Chromic acetate Give 1 g vitamin C, then 120-240 mL water or milk.
Chromic sulfate Do not induce vomiting. Give 120-240 mL water or milk.
Chromic trioxide Do not induce vomiting. Give 1 g Vitamin C, then 120-240 mL
water or milk.
Copper chloride Give water. Induce vomiting.
Chromic nitrate Do not induce vomiting. Give 120, 240 mL milk or water.
copper (II) sulfate Give water. Do not induce vomiting.
Cyclohexane Do not induce vomiting. Give 120, 240 mL water or milk.
Delafield's haematoxylin
soln.		 Give water. Induce vomiting.
Di-n-butyl phthalate Give 120-240 mL water or milk.
Para dichlorobenzene (1-4-dichlorobenzene)
 Give water. Induce vomiting.
Dichloromethane Induce vomiting.
Dichlorophenolindophenol sodium Give water. Induce vomiting.
DCPIP tablets Give water. Induce vomiting.
Diethyl ether Give water. Induce vomiting.
DPX mounting medium Do not induce vomiting. Give 120-240 mL water or milk.
Ethanol absolute Give water. Induce vomiting if patient not drowsy.
Ethyl acetate Give water. Induce vomiting.
Ethylene glycol Induce vomiting.
Euparal Do not induce vomiting. Give 120-240 mL water or milk.
Formalin 40% Immediately administer milk or water, bread. Induce vomiting.
Formic acid Give 120-240 mL milk or water. Do not induce vomiting.
n-hexane Give 120-240 mL milk or water. Do not induce vomiting.
Hydrochloric acid Do not induce vomiting. Give 120-240 mL water or milk.
Hydrogen peroxide Do not induce vomiting. Give 120-240 mL water or milk.
Iodine Give milk or water. Then give milk, starch, or bread to oxidize
iodine to iodide. Induce vomiting.
Kerosene Do not induce vomiting. Give 120-240 mL water or milk.
Lead and lead compounds Give water. Induce vomiting.
Leishman's stain Give water. Induce vomiting if patient not drowsy.
Lithium chloride Induce vomiting.
Lithium hydroxide Do not induce vomiting. Give 120-240 mL water or milk.
Lithium nitrate Give water. Induce vomiting.
Maleic acid Do not induce vomiting. Give 120-240 mL water or milk.
Manganese compounds Give water. Do not induce vomiting.
Mercuric chloride Give water. Induce vomiting.
Mercury and mercury compounds Give water. Induce vomiting if patient not drowsy.
Methanol Give water. Induce vomiting if patient not drowsy.
Methylated spirits Give water. Induce vomiting.
Methyl ethyl kettle Give water. Do not induce vomiting.
Millon's reagent Give water. Induce vomiting.
I-naphthol, (α-napthol) Do not induce vomiting.
Nickel sulfate Induce vomiting.
Nitric acid Do not induce vomiting. Give 120-240 mL water or milk.
Octanol Give water. Induce vomiting if patient not drowsy.
Oxalic acid Give milk or water. Give calcium as milk, weak limewater, chalk.
Pentanol Give water. Induce vomiting if patient not drowsy.
Perchloric acid Do not induce vomiting. Give 120-240 mL water or milk.
Pentan-1-ol Give water. Induce vomiting if patient not drowsy.
Petroleum ether Do not induce vomiting. Give 120-240 mL water or milk.
Phenyl thiourea Give water. Induce vomiting.
Phloroglucin Give milk or water. (Give 30-60 mL of castor oil.)
Phosphorus pentoxide Do not induce vomiting. Give 120-240 mL water or milk.
Phosphorus white Give water. Do not induce vomiting.
Potassium carbonate anhydrous Do not induce vomiting. Give 120-240 mL water or milk.
Potassium chromate Give milk or water. Give 1 g Vitamin C.
Potassium dichromate Give milk or water. Give 1 g vitamin C.
Potassium hydrogen oxalate Give water. Give calcium as milk, weak lime water, chalk.
Potassium hydroxide Do not induce vomiting. Give 120-240 mL water or milk.
Potassium iodide Give water. Induce vomiting.
Potassium nitrate Give water. Induce vomiting.
Potassium permanganate Do not induce vomiting. Give 120-240 mL water or milk.
Potassium thiocyanate Give water. Induce vomiting.
Propanol Give water. Induce vomiting if patient not drowsy.
Isopropyl alcohol Give water. Induce vomiting if patient not drowsy.
Pyrogallol Give milk or water. (Give 30-60 mL castor oil.)
Quinine sulfate Give water. Induce vomiting.
Resorcinol Give milk or water. (Give 30-60 mL castor oil.)
Sebacoyl chloride Give water. Induce vomiting.
Silver salts Give milk or water. Do not induce vomiting.
Soda-lime Do not induce vomiting. Give 120-240 mL water or milk.
Sodium carbonate Do not induce vomiting. Give 120-240 mL water or milk.
Sodium chromate Do not induce vomiting. Give 120-240 mL water or milk.
Sodium dichromate Do not induce vomiting. Give 120-240 mL water or milk.
Sodium dihydrogen orthophosphate Induce vomiting. Give water.
Sodium hydroxide Do not induce vomiting. Give 120-240 mL water or milk.
Sodium hypochlorite Do not induce vomiting. Give 120-240 mL water or milk.
Sodium iodide Give water. Induce vomiting.
Sodium metabisulfite Do not induce vomiting. Give 120-240 mL milk or water.
Sodium metal Remove adhering metal and penetrating particles. Drench skin with water except where contact slight. Rinse mouth thoroughly with
water. Give water.
Sodium oxalate Give milk or water. Give calcium as milk, weak limewater, chalk.
Sodium peroxide Do not induce vomiting. Give 120-240 mL water or milk.
Sodium phosphate Do not induce vomiting. Give 120-240 mL water or milk.
Sodium sulfide Give water. Induce vomiting.
Sulfuric acid Do not induce vomiting. Give 120-240 mL water or milk.
Sodium persulfate Give 120-240 mL milk or water. Do not induce vomiting.
Sodium tartrate Give 120-240 mL milk or water.
Toluene Do not induce vomiting. Give 120-240 mL water or milk.
Trace element mixture Give water. Induce vomiting.
Turpentine (mineral) Do not induce vomiting. Give 120-240 mL water or milk.
Turpentine (vegetable) Do not induce vomiting. Give 120-240 mL water or milk.
Xanthydrol Give water. Induce vomiting if patient not drowsy.