Page 203 - Demo

“Your Safer Source for Science”
Flammable Liquid Safety, continued
Using and Dispensing Flammable Liquids
• If volatile organic solvents are going to be used, the lab must be well ventilated or have a working purge fan to ventilate the lab. The laboratory should also be equipped with one or two ABC, dry chemical fire extinguishers and fire blankets in addi- tion to the other normal safety equipment (safety eyewash, safety shower, etc.).
• Always review the SDS before using any hazardous material in the laboratory.
• Flammable liquids should not be mixed with strong oxidizing agents. As the organic material is oxidized, heat is evolved and may ignite the material resulting in a fire.
• Extreme care must be taken when using flammable liquids around any heat source, flames, or electrical equipment. Laboratory equipment (stirrers, meters, etc.) are designed to be sparkproof, but limiting vapors is always a good safety precaution.
• Organic vapors are heavier than air and will quickly travel along a lab bench or floor to an ignition source. Never use flammable liquids around an ignition source. Try to minimize the amount of volatile liquids used and be aware that organic vapors can travel great distances.
• Flammable liquids are very volatile. Dispense them in an operating fume hood.
• Use lab mats and/or plastic trays when dispensing organic solvents to contain spills and drips.
• Students should dispense flammable liquids from smaller bottles to limit spills and fumes. Larger volume containers increase the possibility of contamination and also increase the amount of fuel that will be available in case of a fire.
• During lab, dispense the flammable liquid from a central dispensing location and have students bring a graduated cylinder or test tube to the dispensing area. This will help to minimize spills and accidents as well as limit the amount of flammable liquid being transported back to the lab bench.
Dispense flammable liquids in an operating fume hood
• Instruct students to remove only the amount of flammable liquid needed for the experi- ment from the reagent bottle. Never add chemicals back to reagent bottles.
• Have spill cleanup materials readily avail- able whenever flammable liquids are used. If a spill occurs, immediately restrict unprotected personnel from the area, remove all ignition sources, and ventilate
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the area. If the spill is too large to contain, the vapors are overpowering, or ignition sources cannot be completely removed, immediately evacuate the school and call the fire department. If the spill is small, contain the spill with sand or an absorbent material. Depending on the spill material and the amount, allow the spilled material to evaporate off the sand or absorbent material in a fume hood or deposit it in a sealed bag or container.
• Absorbent spill pillows are great absorbents for most organic spills. The pillows quickly absorb 10–20 times their weight, making disposal very easy. (See page 153.)
Personal Protective Equipment and Safety Aids
• Consult the SDS for the specific personal protective equipment required and other safety precautions for the flammable mate- rial being used.
• Neoprene rubber gloves are recommended for use when handling organic solvents. Plastic or vinyl gloves will provide some protection against the occasional splash, small spill, and splatter that may occur when using or dispensing solvents.
• Operating eyewashes must be available in any laboratory where chemicals are used. Approved eyewashes must treat both eyes and provide a stream of clean, potable water for at least 15 minutes.
• Chemical splash goggles must be worn anytime flammable liquids are used. Safety glasses are not adequate protection.
• During demos, it is very important that students wear chemical splash goggles anytime flammable liquids are used. The possibility of an explosion or fire always exists and both students and instructors must be protected. If safety goggles are not available, use a heavy duty safety shield to protect your students.
First Aid
• Always seek professional medical attention upon exposure to any hazardous chemical, especially volatile organic solvents. For most organic solvents, the major hazards are flammability and inhalation. If there is a spill or accident, immediately remove any flames, heat, or electrical equipment from the area and begin to ventilate the area.
• If an organic liquid is splashed in the eyes, use an eyewash to irrigate the eyes with fresh, potable water for at least 15 minutes. Make sure the eyelids are held open to properly irrigate them. Ask the victim to look up, down, and sideways to better reach all parts of the eye. After using the eyewash, immediately seek professional medical help.
• If a flammable liquid is splashed onto bare skin, rinse the area with cool water for at least 15 minutes. Many organic solvents will “dry out” the skin and cause minor dermatitis. If the liquid causes burns or other skin irritations, seek medical help immediately.
• If a large amount of flammable liquid is splashed onto clothing, consider removing the clothing immediately and placing the clothing in a fume hood or outdoors. If flammable liquid splashes onto your skin and clothing, remove clothing and then begin rinsing the affected areas with water (using the safety shower is ideal).
• If an organic liquid is ingested, please consult the SDS and immediately call the poison control center (1-800-222-1222) or local hospital emergency room. Follow their directions and seek medical atten- tion as soon as possible. For most organic solvents, the goal is to trap the chemi- cal in the stomach and prevent further injury caused by vomiting. Activated char- coal is sometimes given to help trap the chemical. Do not give the victim anything to drink or induce vomiting unless instructed by a medical professional.
Disposal
• Consult your current Flinn Scientific Catalog/Reference Manual for general guidelines and specific procedures governing the disposal of laboratory wastes. For small amounts of most vola- tile organic liquids, Flinn Suggested Disposal Method #18a, evaporation in an operating fume hood, can be used. For larger amounts, a professional chemi- cal waste disposal firm will have to be used.
• Waste crocks or “slop” buckets are used in many schools for liquid laboratory wastes. Organic wastes should be kept separate from aqueous wastes to prevent any accidental reactions. For organic waste containers, it is best to separate haloge- nated organic solvents (e.g., methylene chloride) from other organic solvents (e.g., ethyl alcohol) for disposal reasons. Sometimes, volatile organic solvents can be evaporated in a fume hood from the organic waste container. Be sure to label all waste containers with their approximate contents. Dispose of all waste solutions as soon as possible.