Lab Specific Safety

Adapted from

Basic Laboratory Methods for Biotechnology

by Lisa Seidman and Cynthia Moore

Risk Reduction in the Lab• Reduce presence of hazards

– Eliminate hazardous material when possible– Substitute less hazardous equivalent

• Reduce risk of inevitable hazards with good lab design– Remove employee from hazard– Contain hazard– Dilute or reduce volume of hazard

• Establish good lab practices for handling hazards– Provide employee training– Practice good housekeeping

• Use personal protective equipment– Provide PPE for all employees– Monitor and enforce its use

Personal Protection in the Lab

• Begins with proper clothing– Clothes should cover all parts of the body– No dangling jewelry or ties– Avoid excessive jewelry on hands or arms– Wear fire-resistant clothing that is easily

removable

Personal Protection in the Lab• Lab Coats are a must

– They are to be worn in the lab at all times, but not in common areas

– They are designed to provide a barrier against harmful agents and prevent contamination of street clothes

– They protect experiments from external contaminants– They should be made of flame resistant and breathable

fabric chosen to fit work hazards and conditions– They are to be kept fastened at all times– Should fit well enough to avoid flapping and have sleeves

long enough to protect arms– They should be laundered regularly and when visibly

soiled

Personal Protection in the Lab

• Shoes– Should have covered toes and nonslip soles

• Sandals, sneakers, woven shoes to be avoided

– Low heels are more appropriate– Can be “dirtier” than the floor itself– Can be “lab-only” or shoe covers may be

worn over street shoes

Personal Protection in the Lab• Gloves

– Provide a barrier between your skin and potential contaminants

– Decide what protection is desired before choosing gloves

– Thickness should be considered– Various types exist:

• Thin-walled• Heavy rubber• Insulated• Puncture resistant

– Manufacturers provide chemical resistance information

• Degradation rate• Permeation rate• Breakthrough rate

Gloves• Choosing and using correct gloves is important for safety• Improper glove use increases risk• Always inspect gloves before wearing• Cover cuts or abrasions on hands before donning gloves• Keep fingernails short and smooth• Choose gloves of appropriate size• Watches and rings may increase exposure risk• Change gloves when exposed soiled and often even if you think

they are clean• Remove gloves in a manner to avoid spreading contaminants from

outside of glove to skin• Wash hands thoroughly after glove use and between changes if you

suspect contamination– Unknown contamination of gloves may cause unintentional spread of

hazardous materials

Glove TypesType Recommended for

Natural rubber latex Bases, alcohols, bloodborne pathogens

Natural rubber blends Same as natural rubber

Polyvinyl chloride (PVC) Strong acids and bases, salts, otheraqueous solutions

Neoprene Oxidizing acids, phenol, glycol ethers

Nitrile Oils, aliphatic chemicals, xylene,

bloodborne pathogens

Butyl Gases, aldehydes, glycol ethers, ketones,

esters

Polyvinyl alcohol (PVA) Aliphatics, aromatics, chlorinated solvents,

ketones (except acetone), esters, ethers

Fluoroelastomer (Viton) Carcinogens, aromatic and chlorinated

solvents

Norfoil (silver shield) Use as glove liner, good for emergency use in chemical spills

Eye Protection• Includes safety glasses, goggles, face shields

– Regular glasses are not a substitute• According to OSHA, 60% of individuals receiving eye

injuries were not wearing protection at all – Remaining 40% not using appropriate devices

• Small flying particles most common• 20% of injuries caused by chemicals• OSHA requires eyewear that:

– Protects against hazards found in that workplace– Fits securely and is reasonably comfortable– Is clean and in good repair– Meets impact resistance and other standards

• Emergency eye wash must be located within 25 feet of lab area in case of accidental exposure

Hazards Requiring Eye Protection

• Explosion or flying particles• Glassware under vacuum• Compressed gases• Corrosive liquids• Cryogenic materials• Liquids that may splash into eyes• Blood and other body fluids that may aerosolize• Radioactive materials• UV light and other radiation

Ear Protection

• Includes earplugs and earmuffs

• Noisy equipment makes sounds that can be uncomfortable or hazardous and require protection

• Long-term unprotected exposure to high noise levels can lead to hearing loss

Respiratory Protection• Masks filter dirt and large particles and provide splash

protection– Most personnel use surgical-type masks

• Air-purification or filtration respirators are needed for infectious droplet or aerosol precautions or when toxic materials are present– Self-contained breathing apparatus in specialized situations

• SCBA contains its own air supply and is used where highly toxic gas exposure could occur

– Respirators are designed to reduce airborne hazards by manipulating the quality of air supply

• Require training to use or may be used incorrectly• Required by OSHA when toxic fumes or hazardous air contaminants

cannot be removed from the environment by other means– Air purification respirators filter room air through canisters of

adsorbant materials that remove specific contaminants from the air

• Require fitting procedures to be effective

Physical Hazards in the Lab• Glassware and sharp objects

– One of most common injuries is cut from broken glass– Inspect glassware for cracks and chips before washing

and before use– Damaged glassware should be repaired or discarded– Always wear hand protection when washing glassware– Sharps are lab items like needles and razor blades that

can cause cuts or lacerations– All sharps and broken glassware are to be disposed of

appropriately

Compressed Gases

• Used by certain pieces of equipment• Stored under high pressure in metal tanks• Gases aren’t problem, pressure is• Cylinders should be handled as explosives• Should be stored upright strapped or chained to

wall or other solid surface• Eye protection should be worn when handling• Valve should be covered with safety cap when

not in use

Heat and Burns

• Bunsen burners, hot plates and autoclaves can result in burn injuries or cause fires

• Don’t leave uncontrolled heat sources unattended• Leave a note when hot plates turned off• Use tongs or insulated gloves to handle hot

beakers and flasks• Never heat sealed containers• Be careful around superheated liquids, they have

been heated past boiling without releasing the gaseous phase

Fire

• A chemical reaction between fuel and oxygen requiring heat or other ignition source– Fuels are any flammable materials

• Substances that will ignite and burn readily in air

• Commonly caused by ignition of flammable organic liquids and vapors– Limiting use and storage of flammable materials can

help reduce fire risk– Limit open flames and other ignition sources as much

as possible• Reduce electrical hazards when possible

Cold Hazards• Due to low temperature freezers, dry ice baths, liquid N2

– Contact with cryogenic substances (temperatures below -78C) may “burn” skin

• Proper hand and eye protection required when working with cold• Cryogenic liquids are not compatible with ordinary glassware,

require Dewar flasks– Heavy multi-walled evacuated metal or glass containers

• Liquid nitrogen supplied in compressed gas cylinders at negative 198˚C – Can cause third degree skin burns– Should never be placed in sealed container

• Dry ice should be handled with insulated gloves– Breathing CO2 vapors could cause hyperventilation or asphyxiation

Lab Electricity Hazards

• Electrical shock is sudden stimulation of body by electricity when body becomes part of electrical circuit

• Keep equipment in good working order and properly grounded– Use GFI circuits that are designed to shut off electrical flow into the

circuit if unintentional ground is detected• Use caution with high-voltage power supplies and

electrophoresis equipment• Use only UL approved equipment to lower risk• Handle electrical equipment only when hands are dry hands• Unplug equipment when not in use• Avoid using extension cords

UV Light

• Nonionizing radiation making up the light spectrum between visible light and X-rays

• Three classes:– UV-A 325-400 nm “black light”– UV-B 280-315nm– UV-C 180-280nm

• Most UV in labs in B and C classes– Transilluminators for visualizing DNA bands in gels

and germicidal lamps• Hand-help UV lamps around 254nm• UV-B and C damage eyes and skin• Its use requires eye and skin protection

Pressure Hazards

• Due to filtration and other procedures carried out under vacuum

• Should be done in shielded enclosure in case of implosion– Collapsing of vessel under low pressure compared with outside

atmosphere• Use face shield and goggles when working with high vacuum

• Use water aspirators to create moderate vacuum– Creates a vacuum through a side arm to a faucet with flowing water– Need a trap for liquid or vapors pulled into the vacuum source

• Autoclaves operate under pressure and heat, producing multiple risks

Chemical Safety

• The MSDS provides information to use for safe handling of chemicals– Lists toxicity, first aid, fire fighting, PPE use, and other

data needed for protection from chemical hazards

• The NFPA ratings on the containers give an idea of hazards posed by the chemicals– NFPA ratings include health, flammability, reactivity,

special or specific hazards

NFPA Chemical Label

Picture taken from http://www.nmsu.edu/safety/images/signs/label_NFPA1.jpg