1 Chemical & Laboratory Safety Training Part 3 – Working with Hazardous Materials Health, Safety & Environment Image:
2 Chemical Storage Never store incompatible chemicals together (SDS will provide information on proper storage) Do not store chemicals: under sinks on top of acid or flammable cabinets directly on the floor in fume hoods Make sure to check expiry dates –some chemicals have a shelf life and must be disposed of Ethers form peroxides which can be explosive Picric and perchloric acids are also explosive when they crystalize/dry out Many other chemicals can become more hazardous as they age, always check the SDS
3 Chemical Storage Store flammables and combustibles in flammable storage cabinets Store chemicals away from exits Make sure chemicals are on secure shelves All chemicals should be stored in well-lit and well-ventilated areas Use trays /tubs for secondary containment
4 Chemical Storage All chemical containers should be properly labeled with WHMIS labels There should not be any cracks or leaks, all containers should be intact (including their lids) Barcodes should be present on all supplier bottles
5 Transporting ChemicalsUse secondary containment when transporting chemicals Use a cart instead of carrying a large tray or bucket Liquid chemicals must be transported in a containment pail
6 Cryogenic Materials Chemicals such as liquid nitrogen, liquid helium, and dry ice have the following hazards: Thermal burns (frost bite) Pressure buildup in closed containers Suffocation (give off vapours that displaces the air in the room)
7 Cryogenic Materials How to protect yourself:When working with small amounts of liquid nitrogen (<5L flasks): Never close the container tightly– pressure buildup will cause the stopper to blow off, or worse, the container may crack/shatter/explode! Only use dewars/flasks specifically designed for cryogenic materials. Not all insulated containers are created equal. A Thermos bottle is not suitable, as they commonly crack and break when filling! Use a loose fitting lid to minimize boil-off and loss of liquid nitrogen, but still allowing for venting of liquid nitrogen gas to avoid over-pressurizing the container Only use in a well ventilated area
8 Cryogenic Materials Standard lab PPE is required to protect against thermal burns: Lab coat Safety glasses Enclosed shoes Long pants (no cuffs) In addition to the above, thermally insulated gloves that are easy to remove quickly should be worn This ensures that if some liquid gets underneath the glove, it can be removed quickly before prolonged exposure to your skin results in thermal burns Avoid wearing watches, rings or bracelets because they can freeze to skin if splashed by cryogens
9 Cryogenic Materials Look what happens when liquid nitrogen spills onto linoleum flooring! It cracks due to the extreme cold
10 Hazard Classes – General PrecautionsAs mentioned, the SDS will give you the majority of the information required to safely handle the hazardous chemical, but the following slides will provide some general information applicable to each hazard class
11 Flammables Flammable aerosols:As with all flammables, protect from heat, but also protect from freezing Minimize the release of flammable aerosol into the air Protect aerosol cans from damage such as drops or punctures Inspect cans for signs of damage or corrosion, do not use if damaged Examples: Spray paint WD-40
12 Flammables Flammable liquids:As with all flammables, protect from heat Do not store in regular refrigerators Check SDS for chemical compatibilities for use and storage Keep only minimal volumes in the lab – Fire Code specifies the quantities allowed Examples: Ethanol Hexane
13 Compressed Gas CylindersYou should always Separate flammable and combustible gases away from oxidizers Store oxygen and fuel gases separately by at least 6 metres (20 feet) or by a wall Store away from doorways, aisles, elevators, stairs Leave the cylinder cap in place until the cylinder is ready for use Valves must be accessible at all times (quick shut-off in case of emergency) Store in the upright position, secure with a chain or belt Use the correct type of regulator Examples: Propane Argon
14 Compressed Gas CylindersTransporting gas cylinders: Use the buddy system as well when transporting full cylinders on the elevator: Never ride the elevator with a full cylinder because if the cylinder starts to leak, you will be trapped in a bad situation Place a sign on the cylinder that says “hazardous materials, please take next elevator” Have one person on the ground floor to put the cylinders in the elevator, and have someone else on the upper floor to meet the cylinder when it arrives Regulator must be off, cap must be on Use gas cylinder carts to move cylinders, be sure to secure the cylinder to the cart
15 Toxic Materials Toxic materials must be stored away from flammables, oxidizers, and reactive materials – to ensure they are not dispersed during a fire or other incident Ensure good ventilation is in place and avoid releasing product into the air (e.g., as vapours/mists/dusts, etc) Keep containers tightly closed Try to eliminate use of these products, or substitute for less toxic chemicals Open containers slowly and carefully to prevent spillage
16 Oxidizers Oxidizers are liquids or solids that readily give off oxygen or other oxidizing substances (bromine, chlorine or fluorine) This means that oxygen combines chemically with the other material in a way that increases the chance of a fire or explosion This reaction may be spontaneous at room temperature or with slight heating Oxidizers do not usually burn by themselves, but they will increase the intensity and speed of a fire by providing more oxygen and will cause materials that normally do not burn by themselves to suddenly catch on fire
17 Oxidizers Compounds containing these functional groups are oxidizers:Peroxides O22- Nitrates NO3- Nitrites NO2- Perchlorates ClO4- Chlorates ClO3- Chlorites ClO2- Hypochlorites ClO- Dichromates Cr2O72- Permanganates MnO4- Persulfates S2O82- Common examples include: nitric acid, perchloric acid, bleach (sodium hypochlorite)
18 Oxidizers Do not use rubber or cork stoppers Don’t heat with oil bathsPerchloric acid can only be used in specifically-designed fume hoods contact HSE if you need to work with perchloric acid Also store oxidizers away from compressed gases, water reactives, strong reducing agents, organic substances and flammable/combustible materials – always check the SDS for other specific incompatibilities Do not use unsealed wooden shelves for storing containers of oxidizers, or use secondary containment trays/tubs if only wooden shelves are available Be very cautious about mixing oxidizers with water, some oxidizers will generate large amounts of heat when they are mixed with water
19 Corrosives Have the ability to corrode materials and human tissueAcids and bases react together, sometimes violently, and must not be stored together Many corrosive materials generate large amounts of heat when they are mixed with water This can cause the solution to froth and boil or even erupt violently For example, a glass of water thrown into a bucket of concentrated sulfuric acid is converted instantly to steam and will eject the entire contents of the bucket into the air
20 Corrosives For this reason: add corrosives to water, not the other way around Always add slowly, in small amounts, with frequent stirring, and always use cold water
21 Corrosives Store corrosives in specified acid or base cabinets, if possible Store these items closest to floor-level, avoid storing above eye level Use secondary containment that is compatible with the acid or base (for example, do not use a metal tray to store acids that are corrosive to metals) Ensure that the secondary containment is large enough to contain the entire volume of the containers it is holding (if the bottles break, will the secondary containment overflow or will it contain the entire volume?)
22 Disposing of ChemicalsEmpty bottles/containers must be triple rinsed before they can be thrown into the regular garbage The labels must be defaced (cross out the chemical names to indicate the container no longer has any chemical in it) Once the bottle is clean, you can reuse it for waste (if the container is compatible with the waste) or bring it to Science Stores for others to re-use If you have to dispose of chemical waste: the Hazardous Waste Disposal form to: before 4:00pm on Tuesdays You can download the form from the website: Health & Safety will reply to your request to confirm, and you will be able to bring the waste down to Science Stores during the “Waste Wednesday” drop-off (10:30am on Wednesdays) If you do not send in a request prior to 4:00 pm on Tuesday, we will be unable to accept the waste
23 Disposing of ChemicalsWaste solvent jugs should not be filled more than 2/3 full This allows for expansion Prevents spillage/overflowing Ensure that filling the bottles does not cause spills (use funnels) Use waste containers that are less than 10L Do not leave waste bottles open with funnel in the top when you do this, you are exposing yourself to vapours
24 Disposing of ChemicalsLabel it well: Hazard Class checked off Chemical names (not abbreviations or molecular formulas) Proportion of each chemical CAS number Supervisor Name and Lab Number Account number Methanol n-propanol Water 30 Waste labels are available at Science Stores
25 Disposing of ChemicalsContain it well: Appropriate containers: Liquids – plastic jugs are great – they won’t break, glass bottles are acceptable too (use rubber solvent buckets to transport) Solids – plastic pails available at Science Stores Clean the outside of the container Lids closed tightly (if lids are cracked/broken, get a replacement from Science Stores) Secondary containment required when transporting – use a cart with raised sides, or transport in buckets, bins, etc Plastic jug Plastic pail Rubber solvent bucket
26 Disposing of Sharps These containers are used for:Needles, scalpels, razor blades, etc (referred to as “sharps”) These containers must be used for all sharps, and are also suitable for sharps that are contaminated with biological and/or chemical materials These items must never be thrown away in the garbage, as they can cause injury to custodial staff, or anyone who might be handling the garbage bags Do not over-fill containers (ensure they are less than 3/4 full) and never force objects into a container Close container prior to transport
27 Disposing of Broken GlassAppropriate glass disposal containers are available in Science Stores – plastic pails with lids, Do not use these containers for intact glassware or chemical containers Do not over-fill pail (3/4 full) and never force objects into a container Close container prior to transport, and use a cart to move heavy pails Again, broken glassware cannot go in the regular garbage (even if it is not contaminated) because broken glass will cut through garbage bags and injure people
28 Conclusion You will only be tested on this material in the online exam at the end of this course You can take the practice checkpoint quiz now, or move on to the next section of the course To move to the next section, please go back to the main CLS UR Courses page. (You may need to refresh your screen to unlock the next section)