Technical information

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• A chemical fume hood is a safety backup for condensers, traps, or other devices that collect vapors
and fumes. It should not be used to "dispose" of chemicals by evaporation unless the vapors are
trapped and recovered for proper waste disposal. For a chemical fume hood to provide significant
protection it must be used and maintained properly by the user;
• The work or apparatus inside the hood should be placed at least six inches behind the sash;
• The fume hood sash should be closed at all times except when necessary to adjust the apparatus
that is inside the hood (when hoods have horizontal sliding panes, the panes should be kept
closed);
• The hood fan should be kept "on" whenever a chemical is inside the hood, whether or not any
work is being done in the hood;
• Personnel should be aware of the steps to be taken in the event of power failure or other hood
failure (e.g. stop work, cover chemicals, close hood, notify Supervisor);
• Physical Plant and the Environmental Medical Service inspect hoods at periodic intervals to be
sure they are working properly.
• Hoods should not normally be used as storage areas for chemicals, apparatus, or other materials.
Environmental rooms are NOT well ventilated and procedures carried out in such rooms should be
carefully designed to minimize personal exposures.
Flammable Liquid Storage
Flammable liquids in quantities greater than 500 ml should be kept in flammable liquids storage cabinets. If
such flammable liquid storage cabinets are not available, the flammable liquids should be kept inside
cabinets and not left on the floor or counters. When flammable storage cans are used, never disable the
spring-loaded closure. Always keep the flame-arrestor screen in place; replace the screen if it is punctured
or damaged. Flammables should not be stored with incompatible materials like oxidizers or in refrigerators
and freezers since most are not explosion-proof or explosion-safe.
Cabinets designed for the storage of flammable materials should be properly used and maintained. The user
should read and follow the manufacturer's information and should also follow these general safety
practices:
• Store only compatible materials inside a cabinet;
• Do not store paper or cardboard or other combustible packaging material with flammable liquids;
• The manufacturer establishes quantity limits for various sizes of flammable-liquid storage
cabinets; cabinet should not be overloaded.
Eyewash Fountains and Safety Showers
All laboratories have been provided with an eyewash connected to the potable water system. Safety
showers are located in the hallways. Users need to know the location and how to operate such devices.
Users need to periodically flush and check the functioning of their eyewash fountains and make sure that
electrical wires and devices are clear of the eyewash. This should be done on at least a quarterly basis.
Facilities Management periodically checks the emergency showers and verifies proper operation. Users are
encouraged to report problems with such safety devices promptly to Facilities Management for evaluation
and repair.
Be sure that access to eyewash fountains and safety showers is not restricted or blocked.
Respirators
• Persons requiring respirators to protect against chemical exposure must contact the MIT
Environmental Medical Service, which will assist in:
• Selection of the respirator;
• Fit testing of the respirator;
• Training on the use, care and limitations of the respirator; and
• Employee medical certification to wear a respirator.
• Surgical masks are not to be used to provide respiratory protection against chemical overexposure.
• The wearing of contact lenses with full-face respirators is not permitted under OSHA regulations.