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What is the difference between a laboratory and any other room at Tufts?
There are three primary differences: containment, decontamination and ventilation. Containment is defined as a room designed to prevent the spread or release of hazardous airborne materials outside the room by special walls, floors, ceilings and doors under normal and emergency conditions such as fire. Decontamination is the ability to remove hazardous materials from the surfaces of the room, supplies and equipment including chairs and desks. Ventilation is the planned supply and removal of air from a space or room. Laboratory ventilation accomplishes four objectives:
The simple answer is that any procedure that results in the production of air contaminants that are toxic, flammable, corrosive, irritating or have a nauseating odor should be conducted in a fume hood.
A more detailed answer is written in the section Guidelines for Fume Hood Use on page 24 of the Tufts Research and Laboratory Safety Guide and provides more specific guidelines for toxic, corrosive and irritating chemicals:
Use a fume for handling any amount of powder, liquid or gas with a TLV or PEL (concentration in air that is safe) of less than 5 ppm or 0.2mg/M3.
Also if the chemical has an Oral Lethal Dose (50%) (oral LD50)in rodents of 10 mg/kg ( this would be a poison).
This information is located on the Safety Data Sheet which each chemical user should review before handling any chemical.
Use a fume hood when handling more than 500 mL of any liquid or gas with a TLV or PEL between 5 and 50 ppm or powders between 0.2 and 2 mg/M3. A chemical will evaporate or become airborne if it has a vapor pressure of 25mmHg at room temperature (20C) or if it is heated or sprayed as a mist.
This information is located on the Safety Data Sheet.
In addition the following rules should be followed when using fume hoods:
Additional rules for use of radioactive materials are located in the TU Radiation Safety Manual.
Biological Safety Cabinets are NOT fume hoods and should not be called “hoods” (it causes much confusion). The TU Biological Safety Manual discusses the selection and use of Biological Safety Cabinets.