Technical information

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name(s). In any event, at the end of each workday, the contents of all unlabeled containers should
be labeled or are to be considered wastes and placed into a properly labeled waste container. If
unlabeled containers of chemicals are discovered, properly label the container if the contents are
known, or call the MIT Safety Office so that the material can be properly identified and disposed.
• All chemicals should be placed in their assigned storage areas at the end of each workday.
• All working surfaces and floors should be cleaned regularly. Always, consider the measures that
should be taken to prevent injury to personnel entering the laboratory to clean, collect waste,
repair or remove equipment, etc.
Procedure-Specific Safety Procedures
Any written laboratory procedures should include a written description of the specific safety practices.
Workers should read and understand these practices and requirements before commencing a procedure.
Specific additional safety procedures follow, in this section, for the laboratory use of chemicals that may
present special hazards.
Procedures for Carcinogens and Highly Toxic Chemicals
For their protection laboratory workers must follow the additional procedures described in this section
when performing laboratory work with any select carcinogen, reproductive toxin, substance that has a high
degree of acute toxicity, or a chemical whose toxic properties are unknown (when using or handling
amounts greater than a few milligrams to a few grams, depending on the substance).
Prior to ordering a "special chemical" the Laboratory Supervisor should determine how to comply with
these additional safety requirements. The Laboratory Supervisor must specify the designated area(s) and
post the boundaries clearly. Only those persons trained by the Laboratory Supervisor to work with the
"special chemical" and informed of its toxicity should use the substance. Such work should be done in the
designated area. All users of special chemicals should conduct their work in accordance with the principles
outlined below:
• Use the smallest amount of chemical that is consistent with the requirements of the work to be
done.
• Minimize personal exposure by the consistent use, as appropriate, of a chemical hood, properly
selected gloves, safety goggles, and laboratory coat that is removed by the individual prior to
his/her leaving the laboratory.
• Use high-efficiency particulate air (HEPA) filters or high-efficiency scrubber systems to protect
vacuum lines and pumps.
• Work on a spill containment tray and/or absorbent pad to facilitate cleanup and decontamination in
case of a spill.
• Prepare for disposal any wastes from work with "special chemicals" as recommended by the
Safety Office.
Procedures for Flammable Chemicals
In general, the flammability of a liquid is determined by its flash point, the lowest temperature at which an
ignition source can cause the chemical's vapor to ignite momentarily in air under certain controlled
conditions.
• Liquids with a flash point below 100oF (37.8oC) will be considered "flammable liquids."
• OSHA standards and the National Fire Protection Association (NFPA) guidelines apply to the use
of flammable liquids in the laboratory. Consultant advice on these Fire Safety Regulations is
available from the MIT Safety Office.
• Quantities of flammable liquids in the laboratory should be kept to a minimum consistent with
laboratory needs and fire code mandates. Flammable liquids or items from which flammable
vapors can evolve (e.g. ether) must not be stored in refrigerators/freezers, since most are not
explosion- proof or explosion-safe.
• Flammable liquids should normally be used only in well ventilated areas away from sources of
ignition.
• Special fire hazard potentials should be assumed to exist whenever oxygen is in use and/or oxygen
concentrations in air are elevated above normal levels.