Osceola District Schools

Osceola District Schools Laboratory Hygiene Program

Module 6: Personal Protective Equipment and Safety Systems

LAB SAFETY EQUIPMENT • A thorough understanding of safety equipment is essential to the any mitigation or damage control efforts a teacher might take. • Fire extinguishers • Safety showers • Eyewash station • Fume hoods • Flammable, corrosive, and explosive chemicals storage • Safety shields

Fire Extinguishers • In order to select the proper extinguisher it is important to examine how fire can be controlled. There are essentially four methods. • Smothering • Cooling • Removing the fuel • Inhibiting the chemical chain reaction

Fire Extinguishers • Methods of extinguishment. • Smothering - few extinguishing agents put the fire out by smothering. The notable exception is the Carbon Dioxide extinguisher. In fact its limited effectiveness is because it is a gas trying to displace another gas (Oxygen). Another agent that acts to smother fires is a Halon replacement gas called FM-200. Some people believe that dry chemicals extinguish the fire by smothering but this simply isn’t true. We know this because dry chemicals extinguish the fire even if the do not settle on the burning material.

Fire Extinguishers • Methods of extinguishment. • Cooling is also not a very common method of extinguishing small fires. It is the primary method of extinguishing large fire however. Water is the agent the does most of this kind of work. Water applied properly to burning wood or paper lowers the temperature the material below its ignition point.

Fire Extinguishers • Methods of extinguishment. • Removal of the Fuel is accomplished by certain fire extinguishers notably aqueous film forming foam on petrochemicals and bicarbonates on cooking grease. In both cases the agent forms a “lid” on the surface of the material and separates it from heat and air. Since the “lid” is on the fuel, no vapors are released. No vapors, no fuel, no fire.

Fire Extinguishers • Methods of extinguishment. • Inhibiting the chemical chain reaction is the Holy Grail of extinguishing agents. Discovered by Dr.Walter M. Haessler these agents substitute a desirable chemical chain reaction for the oxidation process. Monoammonium phosphate dry chemical and vaporizing gas extinguishers are the most common. Halon was the most popular until international restriction of chlorofluorocarbons limited its production.

Review of Fire Classes C Electrical Equipment • wood • cloth • paper • rubber • many plastics A Trash Wood Paper • energized electrical equipment B Liquids Grease D COMBUSTIBLE METALS • gasoline • oil • grease • tar • oil-based paint • lacquer • flammable gases • magnesium • sodium • potassium • titanium • zirconium • other flammable metals D

Fire Extinguisher Anatomy PRESSURE GAUGE (not found on CO2 extinguishers) DISCHARGE LEVER DISCHARGE LOCKING PIN AND SEAL CARRYING HANDLE DISCHARGE HOSE DATA PLATE DISCHARGE NOZZLE BODY DISCHARGE ORIFICE

Fire Extinguisher Types PRESSURIZED WATER • Class “A” fires only. • 2.5 gal. water at 150-175 psi (up to 1 minute discharge time). • Has pressure gauge to allow visual capacity check. • 30-40 ft. maximum effective range. • Can be started and stopped as necessary. • Extinguishes by cooling burning material below the ignition point.

Fire Extinguisher Types (cont.) CARBON DIOXIDE (CO2) • Class “B” or “C” fires. • 2.5-100 lb. of CO2 gas at 150-200 psi (8-30 seconds discharge time). • Has NO pressure gauge--capacity verified by weight. • 3-8 ft. maximum effective range. • Extinguishes by smothering burning materials. • Effectiveness decreases as temperature of burning material increases.

Fire Extinguisher Types MULTIPURPOSE DRY CHEMICAL • Class “A”, “B”, or “C” fires. • 2.5-20 lb. dry chemical (monoammonium phosphate) pressurized to 50-200 psi by nitrogen gas (8-25 seconds discharge time). • Has pressure gauge to allow visual capacity check. • 5-20 ft. maximum effective range. • Extinguishes by inhibiting the chemical chain reaction.

Fire Extinguisher Types (cont.) VAPORIZING GASES • Class “A”, “B”, or “C” fires. • 9-17 lb. Gas Type (pressurized liquid) released as vapor (8-18 seconds discharge time). • Has pressure gauge to allow visual capacity check. • 9-16 ft. maximum effective range. • Works best in confined area--ideal for electronics fire due to lack of residue. Inergen replaced Halon. • Extinguishes by inhibiting the chemical chain reaction

Fire Extinguisher Types (cont.) COMBUSTIBLE METAL • Class “D” combustible metal fires only. • 30 lb. pressurized dry powder optimized for specific combustible metal (also available in bulk containers for hand scooping onto fire to extinguish). • 6-8 ft. maximum effective range. • To activate, must first open nitrogen cylinder on back to pressurize body. COMBUSTIBLE D METALS

Firefighting Decision Criteria • Know school emergency procedures and evacuation routes. • Know locations of extinguishers in your area and how to use them. • Always sound the alarm regardless of fire size. • Avoid smoky conditions. • Ensure area is evacuated. • Don’t attempt to fight unless: • Alarm is sounded. • Fire is small and contained. • You have safe egress route (can be reached without exposure to fire). • Available extinguishers are rated for size and type of fire. • If in doubt, evacuate!

Fire Extinguishers • FLDOE requirements along with those of the State Fire Marshal, Osceola County and other fire authorities should ensure that the right kind of fire extinguisher is located within a short travel distance to any fire in your lab. Should you find it not to be functioning or should you need a 2nd extinguisher use caution in its selection.

Fire Blankets How to use a Fire Blanket 1) Remove the fire blanket from its envelope by grasping the two protruding tags and pulling. 2) How to hold the fire blanket: Grasp one edge of the blanket with each of your hands near a corner. Your thumbs should be on your side of the blanket and your fingers on the side away from you;. ie, palms downward Turn the palms towards each other and continue to turn the hands in that direction until the palms are facing upwards. Lift the arms so that the weight of the blanket is on the tips of the fingers. Turn the hands (fingers still pointing to the ceiling) so that the palms are toward the fire. This action will result in a section of the blanket curling round to protect your hands. Keep your arms up so the blanket will shield your face.

Fire Blankets How to use a Fire Blanket 3) Stand partly side-on to the fire so that one leg is forward and the other back. 4) Move slowly and carefully towards the fire. 5) Let the bottom of the fire blanket touch the side of the bench top or container. 6) Still moving your arms forward, carefully lower the blanket over the top of the container. 7) Place a metal tray or other flat solid object on top of the fire blanket over the mouth of the container.

Fire Blankets How to use a Fire Blanket IMPORTANT NOTES: • If the burning container is over a heating element of any kind, turn off the electricity or gas - preferably, if safe to do so, before extinguishing. • Do not look over the top of the blanket at the fire. • Do not attempt to throw the blanket over the fire.

Spills of chemicals that are reactive to human skin or eye contact with chemicals require fast action in order to prevent loss of sight or serious skin damage. The tool with which all labs are equipped to aid in this are showers and eyewash stations. Chemical Spills on Students or Staff

Using An Eye Wash Station During An Emergency: • Hold eyelids open using the thumb and index finger to help ensure that effective rinsing has occurred behind the eyelid. • It is normal to close eyes tightly when splashed, but this will prevent water or eye solution from rinsing and washing the chemical out. Eyelids must be held open. • Practice of this procedure is encouraged to help familiarize potential users with the feel of rinsing.It will also make it easier for the user to react both promptly and properly to an emergency situation.

Eye/Face Washing Procedures: • Always wash from the outside edges of the eyes to the inside; this will help to avoid washing the chemicals back into the eyes or into an unaffected eye. • Water or eye solution should NOT be directly aimed onto the eyeball, but aimed at the base of the nose. • Velocity of the stream of water must be such that injury to the eye is avoided. • Flush eyes and eyelids with water or eye solution for a minimum of 15 minutes. “Roll” eyes around to ensure full rinsing.

Procedure Continued: • Contact lenses must be removed as soon as possible to ensure that chemicals are not trapped behind the lenses and then the eyes can be completely rinsed of any harmful chemicals. • Medical attention should be sought immediately! Ideally another person in the lab should make contact with responders or dial 911. The sooner medical attention can be given, the chances of not sustaining permanent damage or blindness is greatly improved. • Never Use showers or eyewash with water reactive materials.

Counter Mounted Eye Wash • Plumbed eye wash unit. • Must be between 33 to 45 inches from the floor. Minimum distance of 6 inches from the wall or other obstructions.

Plumbed Eye Wash This unit is built into the wall. To activate, the handle is pulled down and valve is activated.

Self Contained Eye Wash • This unit must hold enough water to dispense a minimum of 0.4 gallons per minute (gpm) for a minimum of 15 minutes. • Typically contain additives to protect against bacteria, fungus, and algae available. • Manufacturer’s fluid change-out schedules shall be rigidly followed.

When a student or staff member is splashed with a chemical the assumption should be that it is dangerous until otherwise proven. Plan for the use of the shower. Never block the routes to showers and don’t worry about flooding. The removal and dilution of the chemical is the key in this situation. Dousing Showerwith Floor Drain

Examples of Poor Shower Maintenance Blocked Path Improper Storage Trip Hazards

Dousing Showers Procedures • Remove contaminated clothing. • Allow copious amounts of water on affected area for a minimum of 15 minutes. • Consult MSDS for emergency procedures. • Clear the room as soon as practicable. • Arrange for medical treatment and replacement clothing or blankets.

Example of Combination Equipment • Combination units • Interconnected assembly of emergency equipment (eye wash and safety shower) supplied by a single source of flushing fluid.

Test Regularly Maintenance Of Eye Wash and Safety Shower: • All shower units must be tested to verify operation. It is recommended that showers be activated monthly to verify operation and to flush lines. This is easy enough to accomplish and should be done routinely. If you do not feel confident in performing a test like this, ask maintenance to do it.

PPE The Last Line of Defense. • Personal Protective Equipment is the last opportunity we have to protect the student and or teacher from the effects of a chemical. The PPE must be the right type, of the right material with the right fit or it is useless. Students must be taught when and how to donn goggles, gloves, aprons etc and how they are doffed to avoid contamination.

PPE TRAINING • When PPE is necessary • What type PPE is necessary • How PPE is to be worn and adjusted • PPE limitations • How to maintain PPE • Useful life of the PPE • Proper disposal of PPE

Eye-protective devices Eye-protective devices should be worn by students, teachers, and visitors in classes at any time at which the individual is engaged in or observing an activity or the use of hazardous substances likely to cause injury to the eyes. Eye protection as well as many forms of PPE present challenges. It is important that the right eyewear be used. Face Shields have real advantages over goggles in that the protect the entire face. Consider the hazard before selecting the PPE.

Eye-protective devicesGlass • When selecting protective eyewear a basic consideration is of what material should they be made? Glass lenses provide good scratch resistance. they can withstand chemical exposure and they can accommodate a large number of prescriptions

Plastic and polycarbonate • Plastic has the advantage of being light weight and they are less likely to fog up. Some newer plastic protective eyewear will accommodate prescriptions but most do not. Plastic is also more affordable than glass. • Another limitation of plastic is that it is not very scratch resistant. They tend to be more stylish and that gets people to wear them.

Safety Glasses Should Be Shielded • Regardless of the material, all safety glasses must be shielded from the sides. Shielding provides better protection from flying debris and it provides protection against chemicals which may be suspended in the air.

Goggles • Goggles provide greater protection from splashes, liquids and dusts than shielded safety glasses. They must be worn correctly for maximum benefit. They should fit tightly against your face and the straps should not dangle from the sides. • Goggles provide the best protection against liquid pesticides and other toxic chemicals. Fogging can be a problem so it is a good idea to treat them with a defogging agent.

Face shields • Face shields are used where you have a very high chance of exposure to an airborne substance. A face shield is not enough to protect your eyes by itself; It should be worn with approved safety glasses. They fog less and offer greater visibility, even with safety glasses, than goggles. If splashes are expected, use a face shield.

Wear goggles or a face shield around chemical gases or vapors, liquid chemicals, acids, or caustics. Turn containers away from the face when opening. Remove protective eye wear only after done with the experiment and the chemicals. Don’t use worn or scratched lens, they discourage use and impair vision. Replace cracked, pitted or damaged goggles or glasses Be certain that protective eye wear is approved for the chemicals you are using. Tips to Protect Your Eyes and Those of Your Students

Using Gloves in the Lab When handling chemicals, it is recommended that the correct gloves be used to protect the worker from accidental spills or contamination. If the gloves become contaminated they should be removed and discarded as soon as possible. There is no glove currently available that will protect a worker against all chemicals. Protection of the hands when working with solvents, detergents, or any hazardous material is essential in the defense of the body against contamination. Exposure of the hands to a potentially hazardous chemical could result in burns, chafing of the skin due to extraction of essential oils ("de-fatting"), or dermatitis.

Using Gloves in the Lab The skin could also become sensitized to the chemical and once sensitized, could react to lesser quantities of chemicals than otherwise would have any effect. Proper selection of the glove material is essential to the performance of the glove as a barrier to chemicals. Several properties of both the glove material and the chemical with which it is to be used should influence the choice of the glove. Some of these properties include: permeability of the glove material, breakthrough time of the chemical, temperature of the chemical, thickness of the glove material, and the amount of the chemical that can be absorbed by the glove material (solubility effect).

Using Gloves in the Lab Glove materials vary widely in respect to these properties; for instance, neoprene is good for protection against most common oils, aliphatic hydrocarbons, and certain other solvents, but is unsatisfactory for use against aromatic hydrocarbons, halogenated hydrocarbons, ketones, and many other solvents. Gloves of various types are available and should be chosen for each specific job for compatibility and breakthrough characteristics. An excellent information is Guidelines for the Selection of Chemical Protective Clothing published by the American Conference of Governmental Industrial Hygienists (ACGIH) or information provided by glove manufacturers.

Using Aprons in the Lab Some operations in the laboratory, like washing glassware, require the handling of relatively large quantities of corrosive liquids in open containers. To protect clothing in such operations, plastic or rubber aprons may be supplied. A high-necked, calf- or ankle-length, rubberized laboratory apron or a long-sleeved, calf- or ankle-length, chemical- and fire-resistant laboratory coat should be worn anytime laboratory manipulation or experimentation is being conducted. Always wear long-sleeved and long-legged clothing; do not wear short-sleeved shirts, short trousers, or short skirts.

Florida Statutes require “Personal protection devices which come in contact with the skin shall be sanitized after each use” FL 6A-2.097 After use, protective eyewear must be cleaned. The exception is if each student is issued their own PPE to use for the entire class. Then they would have to be sanitized before re-issue. Soap and warm water are adequate for cleaning. Care and Maintenance of PPE

Protective Clothing is an important component of safety in the laboratory. It is the last line of defense in protecting students and teachers from exposure. Safety systems are in place to protect teachers and students during laboratory work. These systems require maintenance and safe procedures as backup since it is possible to negate their effectiveness through carelessness. Summary

End of Module Go to the Quiz References

ASE (1996) Safeguards in the School Laboratory (10th ed..), Hatfield: ASE. Borrows, P. (1992) ‘Safety in secondary schools’, in Hull, R. (ed.), ASE Secondary Science Teachers’ Handbook, Hemel Hempstead: Simon & Shuster. (This highlights the common accidents in labs most of which involve chemicals in the eye or mouth or on the body; and describes five ‘main danger areas’ such as burns from alcohol fires and alkali metal explosions.) More recently Borrows has written: ‘Safety in science education’, in Ratcliffe, M. (ed.) (1998). DfEE (1996) Safety in Science Education, London: HMSO. Everett, K. and Jenkins, E. (1991) A Safety Handbook for Science Teachers, London: John Murray. The MSDS Hyperglossary at http://www.ilpi.com/msds/ref/index.html References

29 CFR 1910.1450 – OSHA’s Laboratory Standard also known as Title 29 of the Code of Federal Regulations Part 1910, Subpart Z, Section 1450 Action Level – a concentration designated in 29 CFR part 1910 for a specific substance, calculated as an eight hour-time weighted average (TWA), which initiates certain required activities such as exposure monitoring and medical surveillance. Action levels are generally set at one half the PEL but the action level may vary from standard to standard. Acute toxicity – is the ability of a chemical to cause a harmful effect such as damage to a target organ or death after a single exposure or an exposure of short duration. American Conference of Governmental Industrial Hygienists (ACGIH) – a non-profit organization consisting of a community of professionals advancing worker health and safety through education and the development and dissemination of scientific and technical knowledge. The ACGIH develops and publishes recommended occupational exposure limits each year called TLVs for hundreds of chemicals, physical agents and biological exposure indices. American National Standard Institute (ANSI) – a non-profit organization that administers and coordinates the US voluntary standardization and conformity assessment system. Biological Materials – Biological or biohazardous materials include all infectious organisms (bacteria, fungi, parasites, viruses, etc.) that can cause disease in humans or cause significant environmental or agricultural impact. Carcinogen - A substance capable of causing cancer. Carcinogens are chronically toxic substances; that is, they cause damage after repeated or long-duration exposure, and their effects may become evident only after a long latency period. Glossary Back to Module

Osceola District Schools