5. General Science Laboratory Safety Specifications
In this section
A. Environmental Settings and Considerations
B. Prudent Work Practices
C. Personal Protective Equipment (PPE) Requirements
General science or interdisciplinary science broadly focuses on scientific research, knowledge and inquiry. It is the holistic approach to basic science literacy. In Connecticut schools, science curriculum and assessment (Connecticut Mastery Test or CMTs in Grades 5 and 8, and Connecticut Academic Performance Test or CAPT in Grades 9 and 10) work toward achieving this goal by exposing students to a myriad of science experiences and study. Hands-on, process and inquiry techniques are encouraged through laboratory and field work. To provide exciting and safe science experiences for students, the following safety specifications and prudent practices are highly recommended and in most cases required by regulatory agencies (OSHA, NFPA, ICC, etc.).
A. Environmental Settings and Considerations
- Laboratory Footprint
The science work areas are the first line of defense for safety by design. They include the laboratory, preparation room and storeroom.
Footprint safety hints:
- There should be separate rooms for laboratory activities, preparation rooms and storerooms.
- Furniture placement in laboratories should be designed in such a way as to facilitate easy movement, fast egress, direct observation/supervision and no trip/fall hazards.
- Rooms should have two exits if more than 1,000 square feet (92.9 square meters).
- Legal occupancy loads per National Fire Protection Association (NFPA) and International Code Council (ICC) should be addressed based on 50 square feet (4.6 square meters) net per occupant in a lab. Quasi-legal or academic/professional best practices state that science classes/labs should have no more than 24 students even if the occupancy load limit might accommodate more (NSTA 2004). Research shows that accidents rise dramatically as class enrollments exceed this level (West 2001). This is providing the legal occupancy load is not violated.
- The laboratory should be handicapped accessible relative to furniture, fixtures and more.
- Fume Hood
Definition — A fume hood is an engineering control that provides local exhaust ventilation. It usually has a moveable front sash or window with safety glass. The hood is essential in exhausting hazardous gases, particulates, vapors, etc. It protects both students and teachers from inhalation exposure. Fume hood are usually limited to teacher preparations as opposed to active student use at the middle school level.
Hood safety hints:
- Use the hood to remove airborne chemicals, such as aerosols, dust, fumes and vapors.
- Hoods are not for storage. Keep them clean of chemicals, labware, etc.
- Place apparatus as far back to the rear of the hood for efficient air flow.
- Make sure only necessary materials are under the hood during an operation.
- Always keep the sash between the face and experiment with the sash lowered.
- Check the air flow before and during the operation [Face velocity of 80-120 feet per minute (24.4-36.6 meters per minute)].
- Hoods should be checked and certified operational one to four times a year, depending on frequency of use per manufacturer’s recommendations.
- Never block the air flow into or inside the hood.
- Do not use the hood as a waste disposal device for chemicals.
- Laboratory Ventiliation
Ventilation in a laboratory is critical for a safe and healthy operation. Little or no ventilation can allow the build up of harmful vapors, respiratory symptoms and more.
Ventilation safety hints:
- Occupied Lab air exchange rates should be six to 10 times an hour based on American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) handbook or greater then eight air exchanges per NFPA 45. Contact the director of your school facilities to have the air exchange rate accessed.
- Unoccupied lab air exchange rates, including chemical storerooms, should be four times an hour per NFPA 45.
- Air supplies to labs, storerooms, preparation rooms should never be recycled to any other part of the building, other labs, classrooms and offices.
- Only conduct experiments that the ventilation system can handle. Otherwise, use a fume hood or select an alternate experiment. The idea here is to limit occupant exposure.
- Preventative maintenance programs should be in place to change ventilation filters about four times a year. Filters need to be changed on a quarterly basis.
A good resource for laboratory ventilation is NFPA 45. It addresses required forced air ventilation in science laboratories, including academic labs.
- Utility Controls
Laboratory facilities should have master shut-off devices for utilities such as electricity and gas. Water shut-off devices are usually located outside of the laboratory in a corridor.
- Alarm Sensors
Heat sensors or smoke detectors and fire suppression system sensors are necessary for a safe laboratory, especially during unoccupied times.
- Eyewash and Acid Shower
An eyewash and acid shower are necessary in case of a chemical exposure incident. These devices should be in locations were occupants are provided direct access. OSHA enforces the American National Standards Institute or ANSI (Z358.1-1998) standard, which requires 10-second access to any eyewash/acid shower in the laboratory. Additional eyewash stations are needed if the 10-second access is not possible with one station in the laboratory. Eyewashes require exposure to tepid water [60–100 degrees Fahrenheit (15.6–37.8 degrees Celsius)] for 15 minutes minimum at a prescribed flow rate of 0.4 gallon (1.5 liters) per minute minimum. Preparation rooms also require access to eyewash stations in the same room. Portable eyewash squeeze bottles should not be used. They provide an inadequate water supply and foster the growth of microorganisms.
Acid or safety showers must provide a minimum flow of 30 gallons (113.6 liters) per minute with uninterrupted flow of tepid water.
Eyewashes and showers are not required by code to have floor drains. However, it is prudent and practical to have floor drains for flushing purposes, mold prevention and electrical hazards prevention from standing water.
Eyewashes are required to be inspected (flushed for about three minutes) once a week per the manufacturer’s expectations to clear out sediments, biological contaminants, etc. A written flush log is to be posted next to each eyewash containing the date of flush and person doing the task. OSHA enforces this expectation.
- Safety Shields
In some instances such as demonstrations, safety shields may be advised, in addition to chemical splash goggles.
- Fire suppression
Given the dangers of hazardous chemicals and chances for fire and explosion, fire suppression equipment is an NFPA requirement. Fire extinguishers should be of the A-B-C type (A – combustibles like wood, paper, B – flammables like alcohol, C – electrical)(also type D for combustible metals such as magnesium, potassium, sodium, etc.). Science teachers should be trained annually for proper use of extinguishers. Check with the local board of education policy on employee use for fire extinguishers.
Use the following NFPA “PASS” approach when working with a first extinguisher:
P – Pull the pin
Most extinguishers use locking pin to prevent inadvertent operation. Pulling the pin unlocks the operating level to allow discharge operation.
A - Aim low
Point the extinguisher nozzle at the base of the fire.
S - Squeeze the lever
A lever below the handle or some other type of triggering device must be engaged to release the extinguishing agent.
S - Sweep from side to side
Using a sweeping motion across the base of the fire and continue discharging the extinguishing agent until the fire appears to be out. Be certain to watch the fire area; if the fire reignites, repeat the process.
Signs are to be posted to show the locations of fire extinguishers, particularly in science laboratory areas where they could be easily blocked from view. The signs should be large enough to be seen clearly from a distance. Below is an example of a fire extinguisher sign.
A. Fire extinguisher sign
Portable extinguishers weighing more than 39.7 pounds (18 kilograms) are to be installed so that the top is not more than 3.6 feet (1.1 meters) or above the floor. Those weighing 39.6 pounds or less (18 kilograms or less) must not be more than 5 feet (1.5 meters) above the floor.
Travel distance for Class D portable fire extinguishers is not to be more than 75 feet (22.9 meters) from the hazard [29 CFR 1910.157(d)(6)].
Travel distance for Class ABC portable fire extinguishers is not to be more than 50 feet (15.2 m) or less from the hazard [29 CFR 1910.157(d)(4)].
- Fire Blanket
Flame-retardant wool or other types of materials can be helpful in smothering small fires. Never wrap a standing person on fire in a fire blanket. This can create a “chimney effect.” Wall-mounted canisters or boxes with appropriate signage should be used.
- Goggle Sanitizer
Ultraviolet (U-V) goggle sanitizer cabinets are available and take about 15 minutes to sanitize goggles. Goggles must be sanitized if used by more than one student. Alternatives to sanitizers include disinfectants, alcohol or dish detergent.
- Electrical Safety Controls
All science laboratories, storerooms and preparation rooms should have ground fault circuit interrupters (GFCI) electrical receptacles to protect occupants from electrical shock. This is supported by OSHA relative to the 6-foot (1.8 meters) water source application. However, given that water use can be anywhere in the laboratory (e.g. aquarium, ripple tanks, wave tanks and more), it is prudent to have the total laboratory with GFCI receptacles. One note – touching both metal prongs while plugging into wall receptacle will not protect the user.
B. Prudent Work Practices
Acids are very dangerous and must be handled with extreme care. When diluting acid with water, "AAA" — ALWAYS ADD ACID TO WATER! Slowly stir and swirl the contents, being watchful of the heat produced, particularly with sulfuric acid. An alternative to diluting acids is purchasing diluted acids in lieu of concentrated acids from commercial supply houses.
- Animal Care:
Foster proper handling, humane care and treatment of animals in the classroom and laboratory. Check board of education policies on animal care and use in instruction for the classroom.
- Authorized Access:
Science teachers, department heads, principals and trained custodians are the only employees who should have key access to laboratories, preparation rooms and storerooms. Do not permit unauthorized persons in any science laboratories, preparation rooms or storerooms where hazards exist, e.g., electrical energy sources, hazardous chemicals and sophisticated equipment. OSHA considers science laboratories, preparation rooms and storerooms as secured areas.
- Student Behavior:
- Horseplay or other inappropriate behavior in the laboratory is forbidden.
- Instruct students to never taste chemicals or other laboratory materials.
- Instruct students never to inhale fumes produced during an activity or experiment. Only use the "waft test" if necessary and under the direction of the teacher.
- Instruct students to perform only experiments authorized by the teacher.
- Remind students never to do anything in the laboratory that is not called for in the laboratory procedures.
- Have students follow all instructions, both written and oral.
- Remind students that unauthorized experiments are prohibited.
- Have students report any accident or injury to the teacher immediately, no matter how simple it may appear.
- Instruct students to never return unused chemicals to their original containers.
- Remind students to never remove any materials from the laboratory unless approved by the teacher.
- Remind students to never work in the laboratory without a teacher.
- Chemical Spill Control:
A chemical spill cart should be available to handle small spills in the laboratory. Large spills and leaks require evacuation and the immediate contact of the local fire department's hazmat team. All emergency numbers should be posted in each laboratory with direct means of communications with the front office by phone or intercom. Spill kits can be made in-house or secured through a commercial lab supplier.
Spill kits should include:
- Spill control pillows.
- Neutralizing agents for acid spills (sodium hydrogen carbonate).
- Neutralizing agents for alkali spills (sodium hydrogen sulfate).
- Pick up equipment such as brush, broom, pail, dust pan.
- Personal protective equipment.
- Inert absorbents such as sand or kitty litter.
- Chemical Storage:
- Chemical storerooms are secured areas and must be kept under lock and key with limited access to appropriate certified science staff and paraprofessionals.
- Shelving should be made of finished wood or other chemical resistant material with a front lip approximately 0.75-inch (1.9 centimeters) high.
- Chemicals should not be stored alphabetically. For example, acetic acid and acetlehyde (acetaldehyde) could be adjacent neighbors on a shelf and are an incompatible pair.
- Flammable liquids should be stored in flammable liquid storage cabinets.
- Flammable and combustible cabinets should not be directly vented. Venting of these cabinets is not recommended or required except for odor control of malodorous materials. The openings on the bottom and top of the cabinets should be sealed with bungs supplied with the cabinet. If the cabinets are to be vented, vent from the bottom openings and makeup air from the top openings (NFPA 30, 4-3.2).
- Corrosive chemicals such as acids and bases should be stored in separate appropriate chemical storage cabinets. Store corrosive liquids and solids in separate cabinets.
- Nitric acid should be stored separately from acetic acid in a separate cabinet.
- Lithium, potassium and sodium metals should not be stored or used in a middle school science laboratory.
- All peroxide-forming chemicals (e.g., ethyl ether) should not be stored or used in a middle school science laboratory.
- Heavy items should be stored on lower shelves.
- Never store chemical containers on the floor.
- Chemical storage areas should be kept dry and in a temperature range of 50-80 degrees Fahrenheit.
- Chemical storage should be stored by a compatibility and use system, in addition to being secured behind locked doors and cabinets.
- Chemicals can be separated into organic and inorganic families, and then into compatible and related groups. Compatible groups can be separated by use of different shelves. Only store chemicals alphabetically within a related and compatible group.
Examples of storage groups that are related and compatible (examples are not necessarily recommended for use in middle school):
- Inorganic Family
- Metals, hydrides
- Halides, sulfates, sulfites, thiosulfates, phosphates
- Nitrates (except ammonium nitrate), nitrites
- Hydroxides, oxides, silicates, carbonates, carbon
- Sulfides, selenides, phosphides
- Chlorates, chlorites, hydrogen peroxide
- Borates, manganates
- Other inorganic acids (except nitric acid)
- Sulfur, phosphate
- Organic Family
- Acids, anhydrides, peracids
- Alcohols, glycols
- Hydrocarbons, esters, aldehydes
- Epoxy compounds
- Sulfides, nitrites
Note: Suggested storage groups are listed as a model only. Usage of most hazardous chemicals at the middle school level is not encouraged, e.g., lead and mercury salts, isocyanates, arsenates, cyanides, cyanates and others.
- Chemical Use:**
The following chemicals should be considered for use in hands-on middle school science programs. However, like all chemicals, the teacher has a responsibility to know the character of each chemical or compound by reviewing and applying Material Safety Data Sheet information. Appropriate precautions, PPE, ventilation, etc., are an absolute must for safe use of all chemicals. Please note that this brief list represents the most common types. There are other chemicals that can be considered safe. MSDS need to be reviewed prior to use. Note also that all acids and bases listed are in a dilute, not concentrated form.
A. Chemicals to Use:
- Activated charcoal (carbon)
- Alka-Seltzer tablets
- Alum (several compounds containing aluminum and sulfate)
- Aluminum foil (aluminum metal)
- Ammonia water (ammonium hydroxide)
- Baking powder (sodium aluminum sulfate)
- Baking soda (sodium bicarbonate)
- Beet or cane sugar (sucrose)
- Borax (sodium borate)
- Boric Acid (boric acid)
- Calcium chloride salt (calcium chloride)
- Chalk (calcium chloride)
- Club soda (carbonic acid)
- Copper wire (copper metal)
- Corn starch
- Cottonseed oil
- Cream of Tartar (potassium bitartrate)
- Denatured alcohol (ethanol)
- Epsom Salts (magnesium sulfate)
- Flowers of Sulfur (sulfur)
- Fruit sugar (fructose)
- Grape or corn sugar (glucose)
- Glycerin (glycerol)
- Graphite (carbon)
- Hydrogen peroxide solution (hydrogen peroxide)
- Iron filings (iron metal)
- Olive oil
- Plaster of Paris (calcium sulfate)
- Rubbing alcohol (propanol 2)
- Salt (sodium chloride)
- Table salt (sodium chloride)
- Table sugar (sucrose)
- Vinegar (acetic acid)
- Vitamin C (ascorbic acid)
B. Chemicals Not to Use:
The following list represents common chemicals that may be found in middle school science labs or storerooms and should be removed due to their hazardous nature. Remember that any chemical can be considered hazardous if not used appropriately. Again, consult the MSDS for additional information.
- Ammonium dichromate – (NH4)2Cr2O7 (toxic byproducts)
- Benzene (carcinogen)
- Calcium carbide – CaC2 (explosion hazard)
- Carbon tetrachloride – CCl4 (carcinogen)
- Chloroform (carcinogen) CHCl3
- Concentrated inorganic/mineral acids such as hydrochloric acid – HCl, nitric acid – HNO3 sulfuric acid – H2SO4 (corrosive, serious burn and eye hazard)
- Copper sulfate (toxic)
- Diethyl ether (forms explosive peroxides)
- Dry ice – carbon dioxide (frostbite and blisters)
- Elemental mercury – Hg (highly toxic)
- Elemental potassium – K (forms explosive oxides)
- Elemental sodium – Na (dangerous reactions with water)
- Formaldehyde – HCHO (carcinogen)
- Hydrogen sulfide – H2S (toxic vapors)
- Iodine – I2 (respiratory irritant)
- Lead compounds such as lead chloride – PbCl2 , lead nitrate – Pb(NO3)2 (one or more are potential carcinogens, toxic)
- Magnesium strips – Mg (burn hazard)
- Mercury salts such as mercuric sulfate – HgSO4 (toxic)
- Methanol or methyl alcohol – CH3OH (toxic)
- Mineral talc – Mg3Si4O10 (can cause asbestosis)
- Picric acid – 2,4,6-trinitrophenol (explosive crystals)
- Potassium chlorate – KClO3 (can cause violent reactions)
- Silver cyanide – AgCN (toxic)
- Sodium Hydroxide – NaOH (caustic)
- Vinyl Chloride – CH2=CHCl (carcinogen)
- White phosphorous – P (fire hazard)
**Reprinted by permission from NSTA Scope on Safety, Nov./Dec. 2004.
Do not wear loose/baggy clothing or dangling jewelry. They are a safety hazard in the laboratory. Make sure long hair is tied back behind the ears. Acrylic nails are flammable and should not be exposed in the laboratory.
- Cold/Heat Protection:
When dealing with cryogenic or very hot materials, use heat-safety items such as safety tongs, mittens, aprons and rubber gloves.
- De-energizing Equipment:
De-energize all equipment when leaving the laboratory. Examples include unplugging equipment (like microscopes), shutting off gas valves (use the master gas shutoff), and shutting off all water faucets.
- Evacuation Drills:
Establish, provide signage and practice laboratory evacuation drills based on NFPA and OSHA regulations in case of fire or other incidents. Gas and electricity should be shut off during evacuations.
Keep all exits and safety equipment free from obstructions in any way. No materials should be stored in the corridors.
Plumbed eyewash stations should be flushed for about three minutes a week as recommended by the National Safety Council and ANSI (Z358.1 Emergency Eyewash & Shower Equipment). A recording log of flushing activity/inspections is required on the device.
- First Aid:
First aid kits should be available in each laboratory along with a written phone number for the school nurse's office for medical support in case of an incident. Check with the board of education's policy on employees administrating first aid.
- Food, Drink and Cosmetics:
Eating, drinking and the use of cosmetics are prohibited in areas where hazardous chemicals or biohazards are stored or in use.
Use caution when inserting and removing glass tubing from rubber stoppers. Lubricate glassware (tubing, thermometers, etc.) before attempting to insert it in a stopper. Protect your hands with towels or gloves when inserting glass tubing into, or removing it from, a rubber stopper.
Chipped, cracked or scratched glassware should never be used in the lab.
Broken Glassware: Broken glassware must be placed in a box or hard plastic container with a plastic liner. Include appropriate signage.
Always use glass drying racks to support glassware when drying.
Never leave an active burner unattended. Never leave anything that is being heated or reacting unattended. Remember to turn off the burner or hot plate when not in use. Remember to give hot items time to cool down before handling. Otherwise, use protective gloves and equipment (tongs, etc.).
Work areas should be kept clean at all times. Students should only use laboratory instructions, worksheets and necessary equipment in the work area. Other materials such as backpacks, books, purses and jackets should be stored in the classroom area or lockers. Orderliness is required in science laboratories by the OSHA housekeeping standard.
Green Cleaning Program and Laboratory Applications:
As of July 1, 2011, each local and regional board of education in Connecticut shall implement a green cleaning program for the cleaning (Substitute House Bill No. 6496 Public Act No. 09-81 2 of 7) and maintenance of school buildings and facilities in its district. No person shall use a cleaning product inside a school unless such cleaning product meets guidelines or environmental standards set by a national or international environmental certification program approved by the Department of Administrative Services, in consultation with the Commissioner of Environmental Protection. Such cleaning product shall, to the maximum extent possible, minimize the potential harmful impact on human health and the environment. (c) On or before April 1, 2010, the Department of Education, in consultation with the Department of Public Health, shall amend the school facility survey form to include questions regarding the phase-in of green cleaning programs at schools. (d) On or before October 1, 2010, and annually thereafter, each local and regional board of education shall provide the staff of each school and, upon request, the parents and guardians of each child enrolled in each school with a written statement of the school district's green cleaning program. Such notice shall include (1) the types and names ofenvironmentally preferable cleaning products being applied in schools, (2) the location of the application of such cleaning products in the school buildings and facilities, (3) the schedule of when such cleaning products are applied in the school buildings and facilities, (4) the statement, "No parent, guardian, teacher or staff member may bring into the school facility any consumer product which is intended to clean, deodorize, sanitize or disinfect.", and (5) the name of the school administrator, or a designee, who may be contacted for further information. Such notice shall be provided to the parents or guardians of any child who transfers to a school during the school year and to staff hired during the school year. Each local or regional board ofeducation shall make such notice, as well as the report submitted to the Department of Education pursuant to subsection (a) of section 10-220.
This includes glass cleaners, hand cleaners, general purpose cleaners and more. Green cleaners contain no fragrances, have low volatile organic compounds or VOCs, perform well and have minimum health effects.
Science labs are havens for biologicals (mold, mildew, bacteria, animal dander, etc.) and physicals (particulates, chemical vapors, etc.). In the spirit of the statute, middle school science teachers need to work with custodians in effort to transition into the use of greener cleaning products. From the science curriculum side, improved choices need to be made relative to safer alternatives to hazardous laboratory chemicals and also adopting the microchemistry approach.
The Green Schools Initiative and the Green Purchasing Institute recommend the following approach (Green Schools.Net – Best Practices for Disinfection):
Clean first: Disinfectants and sanitizers don't penetrate the dirt/microbe barrier effectively. Before applying disinfectants or sanitizers, surfaces should be thoroughly cleaned with soap and water or other green cleaner if possible.
Determine where and when disinfectants are needed: Use low-level disinfectants on surfaces in the lab that hands directly touch – benches, sinks, faucets, etc. If there is an incident resulting in blood or other potentially infectious materials (OPIMs), a high-level disinfectant should be used.
Follow manufacturers' instructions regarding proper dilution, application and rinsing procedures, and dwell time: Disinfectants need to saturate a surface usually for 1-10 minutes "dwell time" to be effective. Check the manufacturer's label!
Carefully Select Antimicrobial Products: School districts can determine the product efficacy by reviewing information on the product label as well as registration information on file with the US EPA. School districts should avoid products containing ortho-phenylphenol and minimize their use of chlorine bleach, quaternary ammonium compounds ("quats"), and pine oil as much as possible because these "active ingredients" are known to cause asthma, severe respiratory effects, and other serious health risks. Instead, look for asthma-safe disinfectants and sanitizers that use hydrogen peroxide, citric acid, and thyme oil to kill bacteria, viruses and other organisms.
Consider Switching to Asthma-Safe Disinfectants and Sanitizers: Download the Directory of Asthma-Safe Disinfectants and Sanitizers, which provides details on several asthma-safe disinfectants and sanitizers.
Personal hygiene is required before and after laboratory work by washing hands with soap and water.
- Hazard Rating System:
Laboratories, preparation room and chemical storage areas should have the NFPA diamond with the highest hazard ratings of chemicals in the room posted.
- Inventory – Chemicals:
Be certain to have a complete and up-to-date chemical inventory based on OSHA's HazCom Standard. The following information is suggested: names of chemical, storage location, date of purchase, and amount on hand. OSHA requires only the identity name referenced in the MSDS or common name/trade name. Hazard information is not required in the inventory because the employee can secure that information from the MSDS. The inventory should be ongoing and current at all times.
Labeling is required of all chemical containers. All labels must be legible, in English and include chemical/product name. Chemical information related to relevant hazards must also be evident. All chemicals are to have labeled containers with appropriate information, e.g., Product identifier
Supplier identifier, Chemical identity, Hazard pictograms, Signal words, Hazard statements and Precautionary information.
Additionally, the revised 2012 OSHA HazCom notes the following relative to labeling:
- 1910.1200(f)(6) Workplace labeling. Except as provided in paragraphs (f)(7) and (f)(8) of this section, the employer shall ensure that each container of hazardous chemicals in the workplace is labeled, tagged or marked with either:
- 1910.1200(f)(6)(i) The information specified under paragraphs (f)(1)(i) through (v) of this section for labels on shipped containers;
- or, 1910.1200(f)(6)(ii) Product identifier and words, pictures, symbols, or combination thereof, which provide at least general information regarding the hazards of the chemicals, and which, in conjunction with the other information immediately available to employees under the hazard communication program, will provide employees with the specific information regarding the physical and health hazards of the hazardous chemical.
- 1910.1200(f)(8) The employer is not required to label portable containers into which hazardous chemicals are transferred from labeled containers, and which are intended only for the immediate use of the employee who performs the transfer.
However, in a middle school laboratory, all portable containers need to be labeled. Should there be a safety incident, it is critical to know what hazardous chemical was being worked with in the lab or preparation room area.
- Safety Data Sheets (SDS):
SDS for all hazardous chemicals must be kept in a place which is easily available to employees. For easy access during a medical emergency or safety incident, SDS for chemicals being used on a particular day should be posted in the laboratory. As part of the laboratory safety preparation for an experiment, all appropriate SDSs should be reviewed with students. SDSs must be maintained by the employer for at least 30 years. Computer terminals or fax machines that allow employees to read and refer to the SDS are permitted to be maintained at the jobsite, in lieu of paper copies, as long as no barriers to access exist.
A list of the hazardous chemicals known to be present using an identity that is referenced on the appropriate MSDS (the list may be compiled for the workplace as a whole or for individual work areas) is required. [1910.1200(e)(1)(i)]
- Microwave Ovens:
Microwave ovens are used for life science activities such as heating water. Never use containers with lids on them in a microwave. Never place metallic objects, aluminum foil or metal pots, in a microwave. Students should be instructed on their proper use. Occupants with pacemakers should not work in the proximity of a microwave oven. Proper signage warning of microwave use should be posted outside the laboratory door.
- Personal Protective Equipment:
Make sure appropriate personal protective equipment is used, e.g., gloves, apron, chemical splash goggles (safety glasses for projectiles, solids), closed-toe foot protection.
- Pipette Procedure:
Use a suction bulb when filling pipettes, not mouth suction.
- Planning for Experiments/Demos:
Perform experiments or demonstrations prior to assigning the activity to students. Provide verbal and written safety instructions to students.
Consumable food must not be placed in the same refrigerator as chemicals or biohazard material. Refrigerators used for nonconsumable materials should be labeled "Contents Not For Human Consumption." Use appropriate signage on the doors of both types of refrigerators.
- Safety Hazards:
Science teachers should be vigilant in doing safety inspections in the laboratory. Report any existing and potentially hazardous safety violations to the science supervisor and principal in writing. Do not conduct science activities without appropriate and functioning safety equipment.
- Safety Rules:
Safety rules should be posted in a visible place.
- Safety Strategies:
- Never leave students unsupervised in a laboratory or science classroom.
- Students should read and sign lab safety contracts prior to doing any laboratory activities.
- Safety procedures should be reviewed by the teacher with students prior to laboratory work.
- Take action to insure student accountability, such as testing of safety procedures.
- Never overlook any safety infraction. Direct teacher/student intervention supervision is essential.
- Document all safety planning initiatives in plan book.
- Instruct students in the proper use of all safety equipment.
Pins, knives, needle probes and scissors should be used with extreme care. Sharps to be discarded should be placed in a separate, rigid container labeled "SHARPS ONLY."
Have the appropriate signage installed/posted for the following items: exits, eyewash station, fire blanket, fire extinguisher, goggle sanitizer, master shutoffs, safety shower, spill kits and waste containers.
- Waste Disposal (Items to Be Recycled):
Dispose of all chemical waste properly as noted by the teacher or MSDS. Chemicals should never be mixed in sink drains. Sinks should only be used for water and those solutions noted by the instructor. Solid chemicals, filter paper, matches and all other insoluble materials are to be disposed of in the properly labeled waste containers. Cracked or broken glass should be placed in the special container for "Broken Glass."
Waste disposal or items to be recycled should be done on an annual basis. There needs to be appropriate storage and labeling.
C. Personal Protective Equipment (PPE) Requirements:
- Eye Protective Devices
Eye protection is required by Connecticut state statute where the process used can cause damage to the eyes or where the protective device can reduce the risk to injury. For example, students in a ninth-grade science class using meter sticks for measurement gathering or launching rockets should have safety glasses with side guards at a minimum. If hazardous chemicals such as acids are being used, chemical splash goggles are required. The general guide is as follows:
Chemical Splash Goggle (indirect vents and ANSI impact standard Z87.1) when using hazardous liquids or solids.
Safety glasses (side shields and ANSI impact standard Z87.1) when using solids or projectiles.
Eye protection should be hygienically cleaned after each use via UV goggle sanitizer, alcohol wipes or detergent and warm water.
All K-12 schools in Connecticut are required to have the State Goggle Statute Section 10-21 4a-1, (including chart and precautions) posted in science laboratories. The signage must be in clear view for occupants to see.
Regulations Concerning Eye Protective Devices
As Authorized by Section 10-21a
of the Connecticut General Statutes
The regulations of Connecticut state agencies are amended by adding sections 10-21 4a-1 to 10-21 4a-3, inclusive as follows:
Section 10-21 4a-1. By whom, when and where eye protective devices shall be worn: definitions. Any person who is working, teaching, observing, supervising, assisting in or engaging in any work, activity or study in a public or private elementary or secondary school laboratory or workshop where the process used tends to damage the eyes or where protective devices can reduce the risk of injury to the eyes concomitant with such activity shall wear an eye protective device of industrial quality in the manner in which such device was intended to be worn. For the purposes of sections 10-21 4a-1 to 10-21 4a-3, inclusive, "workshop" and "laboratory" shall include any room or area used to teach or practice industrial arts, vocational and technical education; science, arts and crafts, or any similar skill, activity or subject. The following list of sources of danger to the eyes and the type of protection required to be worn in each case is exemplary, not exclusive.
Source of Danger to the Eyes
Type of Protection Required
a) Caustic or explosive chemicals
Clear goggles, splash proof
b) Explosives, solids or gases
c) Dust producing operations
Clear goggles, splash proof
d) Electric arc welding
e) Oxy-acetylene welding
Colored goggles or welding helmet
f ) Hot liquids and gases
Clear goggles, splash proof
g) Hot solids
Clear or colored goggles, or spectacles
h) Molten metals
Clear or colored goggles
i) Heat treatment or tempering of metals
Clear or colored goggles
j) Glare operations
Colored spectacles or goggles, or welding helmet
k) Shaping of solid materials; chipping, cutting, grinding, milling, sawing, stamping
Clear goggles or spectacles
l) Repairing or servicing of vehicles when hazard is foreseeable
Clear goggles or spectacles
m) Spraying and dusting
Clear goggles, splash proof
n) Other similar activity being conducted in the instructional program which risks damage to the eyes
Proper eye protective device
Section 10-21 4a-2. Minimum standards for the design, construction and quality of eye protective devices used in schools. Any eye protective device used in such school workshops or laboratories shall be designed and constructed to resist impact, provide protection against the particular hazard for which it is intended, fit snugly without interfering with the movements of the user and be durable, cleanable, and capable of frequent disinfection by the method prescribed for such device by the school medical adviser.
All materials used in such eye protective devices shall be mechanically strong and lightweight, non-irritating to perspiring skin and capable of withstanding washing in detergents and warm water, rinsing to remove all traces of detergent and disinfection by methods prescribed by the school medical adviser without visible deterioration or discoloration. Metals used in such devices shall be inherently corrosion resistant. Plastics so used shall be non-flammable and shall not absorb more than five percent of their weight in water.
Section 10-21 4a-3. Responsibilities of public and private elementary and secondary school governing bodies. The governing board or body of each public and private elementary and secondary school in the state shall require the use of appropriate eye protective devices in each laboratory and workshop by any person in such areas during any activity engaged in, and shall post warnings and instructions in laboratories and workshops which include the list of hazards and protection required set form in Section 10-21 4a-1. Such boards shall make and enforce rules for the maintenance of all eye protective devices in clean, safe condition and shall replace any such protector which becomes irritating to the skin.
Purpose: To direct the school administrators in the kinds, construction, times and uses of devices for eye protection of teachers and pupils in school laboratories and workshops.
Connecticut Law Journal, January 9, 1968
- Face Protection
Eye protection leaves the face exposed. In certain instances, additional PPE is required beyond eye protection. Face shields protect against most splashes of severely corrosive materials and flying particles. A better solution is to use a fume hood with the sash down as a face barrier.
- Hand Protection
OSHA Hazard Communications and Laboratory Standard required PPE for hands. Gloves are designed for very specific types of situations. One type of glove does not fit all needs. The manufacturer's claims should be reviewed and followed. Gloves should only be used under the conditions for which they were designed.
Types of gloves appropriate for secondary schools include:
- Latex/vinyl (microorganisms and biological material – latex is a known allergen for some people and therefore should be avoided);
- Neoprene (solvents).
Check Material Safety Data Sheets for the appropriate type of glove for maximum protection.
Glove removal is effected by peeling one off of your hand starting at the wrist, moving toward the fingers. Don't allow the surface of the exposed glove to come in contact with the skin. When one glove is removed, use it to peel off the remaining glove.
- Foot Protection
For laboratory work, students should be wearing closed toed shoes or sneakers. No flip flops or sandals are allowed. This protects the feet from falling objects such as spilled chemicals, weights, rocks, etc.
Aprons are required to protect clothing and skin from spills, splashes, etc. On absorbent type aprons are the best. Make sure they are the appropriate length - just below the knees to prevent trip/fall hazards if too long.
The greatest protection is from long pants and long sleeve shirts/blouses. This again protects the skin.
American National Standards Institute
National Fire Protection Association
National Science Education Leadership Association
National Science Teachers Association