A variety of chemicals are used in the biology department, some of them potentially hazardous. Employees have a right to understand what their risks are in the workplace and how to minimize the risk to their health.
Understanding the difference between toxicity and hazard is important. Toxicity is the inherent ability of a substance to cause adverse health effects. Hazard refers to the likelihood that adverse health effects might occur. Exposure links toxicity and hazard. Without exposure, a toxic chemical cannot cause adverse health effects.
Exposure can occur in three general ways, ingestion, skin contact and inhalation.
Ingestion can occur by mouth pipetting, which is why this technique is banned. The more frequent method of ingestion occurs by hand-to-mouth transfer. Thus no food or drink is allowed in laboratories, and hand washing is critically important. Ingestion of small doses of toxic substances over time can cause systemic diseases, such as central nervous system disorders, kidney and livery dysfunction, and cancer.
Skin contact includes absorption through the skin and reaction on the skin surface causing dermatitis. Cuts, abrasions, dermatitis provide an easier route for absorption than intact skin. Personal protective equipment such as gloves, impervious sleeves, lab coats, face-shields and goggles are used to minimize skin contact. Systemic disease can result from skin contact of toxic substances. Dermatitis with reddening, drying and itching can also occur with detergents; corrosives can cause severe burns.
Inhalation can result in respiratory irritation or in pulmonary or systemic effects. Reduction of inhalation hazard requires use of local exhaust systems, such as a fume hood.
Exposure to toxic materials can cause either acute or chronic health effects. Acute effects occur soon after the initial exposure, with the exposure being relatively high and comparatively brief. Chronic effects are often not noticed until long after initial exposure. Repeated low-level exposures can cause cancer or other systemic diseases. However, it is very difficult to correlate cancer with exposure to any specific agent.
Generally, the larger the dose, or exposure, the greater the response will be. Material Safety Data Sheets often contain LD50 data. LD50 refers to the lethal dose required to kill 50% of the test animals. If an LD50 value is low, for example less than 500 mg/kg versus 5 g/kg, that means that material is very toxic. A small amount can kill 50% of the animals.
Permissible Exposure Limits (PEL) or Threshold Limit Values (TLV) have been established for many chemicals. Threshold Limit Values are the airborne concentrations of a material that yields no adverse health effect when inhaled forty hours a week over a working lifetime. Table E of the CSB/SJU Chemical Hygiene Plan lists many chemicals and their PELs or TLVs.
Health effects of overexposure to various classes of chemicals include:
Solvents can cause narcotic effects and central nervous system disorders. Eye or mucous membrane irritations can also occur. Chronic exposure can result in dermatitis and system effects.
Corrosives usually produce acute effects, including eye, mucous membrane, and upper airway irritations. Dermatitis and severe burns can occur with skin contact, and bronchitis can develop with chronic exposure.
Poisons can cause systemic disease, or fatality.
Consult the MSDS for other classes of chemicals.
Most methods of detection rely on the observations of laboratory workers. Observation of vapors, particulates, and odor can alert workers to dangerous exposures. Environmental monitoring is required for some chemicals such as formaldehyde. Formaldehyde vapor monitors are available.
Read the MSDS for the chemicals you will be using. Know the location of emergency equipment.
No food, drink, or application of cosmetics in laboratories. Do not mouth pipette.
Do not work alone. Avoid distracting or startling other workers when they are handling hazardous chemicals.
Wear appropriate laboratory attire, and personal protective equipment. Do not wear contact lenses when working with hazardous chemicals.
Keep your work area uncluttered.
Use the smallest quantity possible of a chemical.
Confirm that the fume hood is functioning properly. Exhaust rate for all fume hoods except in NSC 219 should be 100 LFPM. NSC219's fume hood exhausts at 120 LFPM. Use a fume hood when working with a level 3 or 4 chronic toxic chemical or a level 4 acute toxic chemical. A fume hood should also be used whenever the PEL is less 50 ppm; or whenever working with flammable chemicals that might produce vapors approaching one tenth of the lower explosive limits.
Provide chemical information in a standard format developed by OSHA. A MSDS includes the identification of the material; physical data,; fire and explosion hazard; reactivity hazard; health hazard information including the PEL or TLV if known; spill and disposal techniques; and personal protective equipment.
CSB/SJU biology department MSDS are stored in NSC130.
Embryotoxins: Wear gloves and keep contact to a minimum. If you are a woman of childbearing years, use the embryotoxin only in a fume hood.
Moderate to high chronic or high acute toxicity chemicals--affected chemicals are listed in Tables A-1 and A-2 in the CHP. These chemicals are stored in a "Restricted Access" area, and usage logs must be maintained. Use a fume hood when measuring quantities of pure chemicals with a "Caution: Moderate-High Chronic or High Acute Toxicity Chemicals in Use" sign. Wear gloves and goggles. Disposable impervious smocks, or aprons and sleeves must be used if the material is a high chronic toxicity chemical, or spills can be reasonably anticipated. Decontaminate work area after use. Dispose all solid waste in specially marked containers, and label completely. Wash hands and arms immediately after working with these chemicals.
Flammable chemicals: Use bonding and grounding cable when transferring quantities in excess of one gallon. Keep in covered containers and away from all sources of ignition, high heat, and combustion. Dispense all solvents in a fume hood.
Explosives, Highly Reactive Chemicals and Oxidizers: Dispose of peroxide-forming chemicals within one year of opening. Do not mix even small quantities with other chemicals without prior knowledge of the hazards possible.
Leave the spill area. Alert others in the area and direct/assist them in leaving.
Without endangering yourself: remove victims to fresh air, remove contaminated clothing and flush contaminated skin and eyes with water for 15 minutes. If anyone has been injured or exposed to toxic chemicals or chemical vapors, call 911 or 2144 and seek medical attention immediately.
Close doors and isolate the area. Prevent people from entering spill area.
From a safe place, call the Life Safety, 911 or 2144.
Report that this is an emergency and give your name, phone and location; location of the spill; the name and amount of material spilled; extent of injuries; safest route to the spill.
Stay by that phone until advised otherwise.
Fire Department will clean up or stabilize spills that are considered high hazard (fire, health or reactivity hazard). In the case of a small spill and low hazard situation, the Fire Department may advise you on what precautions and protective equipment to use.
Until emergency response personnel arrive: block off the areas leading to the spill, lock doors, post signs and warning tape, and alert others of the spill.
Post staff by commonly used entrances to the area to direct people to use other routes.
Careful consideration of the chemical hazards involved must be undertaken to assess how to clean up a spill safely. Consult the MSDS for the chemical involved. Ultimately the responsibility rests with the supervising faculty or staff member to assess the risks involved, and assign appropriate personnel and equipment to clean up the chemical spill.
Spills of chemicals will health, flammability, and reactivity ratings of less than three can be cleaned by student workers.
Small spills (no more than 50 ml) with health, flammability, and reactivity ratings greater than three can be cleaned by a student worker under the supervision of a faculty or staff member.
Spill clean-up procedure:
Alert others in the area.
Clean up the spill using the appropriate protective equipment and spill-clean-up materials. Chemical Spill Clean-up kits are found in each unit and are appropriate only for spills less than 50 ml. These spill kits contain kitty litter, scoops, and Ziploc plastic bags. Universal absorbent pillows with a capacity of up to four liters are available in the chemical stockroom (NSC130).
-Acid or Base Spills: Neutralize the spill before cleaning up.
-Dry powered chemicals: Reduce the dust raised by using damp paper towels.
Place the chemical and absorbent material into appropriate containers.
Tightly seal the container, and label the container with a complete list of contents and relative amounts.
Place the container in NSC 130 on appropriately labeled shelving and alert a
Immediately take the victim to the nearest eyewash station.
Flush the eyes for at least 15 minutes.
Hold the eyelids open, while continuously rotating the eyeballs to flush all of the chemicals from the eye.
Call Life Safety Services (911 or 2144). The officer will assess the situation, and arrange for further medical treatment. Further medical attention is required
Call the Poison Control Hotline (1-800-222-1222) for advice on first aid.
Do not induce vomiting unless specifically instructed to do so by trained medical personnel.
Skin contact by chemicals over a larger portion of the body:
Help the injured person to the safety shower, and flush exposed skin for at least 15 minutes. Remove goggles only after washing their head. If the eyes have also been exposed, the victim should bend over to flush their eyes while the shower is running.
Enlist the assistance of a staff person, or someone of the same gender as the victim. Usually, three or four people are necessary to help the victim.
Cut contaminated clothing away with scissors (stored near the safety showers) to avoid contaminating the victim's face and eyes.
Remove all layers of contaminated clothing, shoes, and jewelry. If clothing or jewelry adheres to a chemically burned area of skin, do not pull it away.
Call Life Safety Services (911 or 2144). The officer will assess the situation and arrange for further medical attention. Further medical attention is required.
Move the victim to an area of fresh uncontaminated air.
Remember that hot gases rise, but most chemical vapors are heavier than air.
Call Life Safety Services (911 or 2144). The officer will assess the situation and arrange for further medical attention.
Appendix C of the CSB/SJU Biology Department Chemical Hygiene Plan includes a list of chemicals that can be disposed in a sewer or landfill. If the chemical is not on this list, treat it as potentially hazardous waste.
Collect the chemical waste in a tightly closing container, preferably plastic. Label the container completely with the contents and relative concentrations. Include the date and the name of the employee generating this waste. Do not fill the container more than three-fourths full.
Place the container in NSC 130 on appropriately labeled shelving. Contaminated, unpreserved, animal waste should be placed in a labeled freezer.
Alert Carol Jansky or another member of the Biology Department Safety Committee.