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Evaluating lab procedures

  • What are the hazards of the chemicals used in the procedure? Use the SDS as a source of information.
  • Are any of the chemicals on the NYCFD list of banned chemicals? For a quick reference, refer to the online Science Safety Manual by the New York City Department of Education.
  • Are flammable liquids required in the lab procedure?
    • If so are the quantities of flammable liquids very small — less than 10 milliliters? Experiments with flammable increase the risk of fire and should not be used.
    • If small amounts of flammable liquids are used will any ignition sources be involved? If ignition sources are present the experiment should not be used.
  • Are any carcinogenic substances used? For a quick reference, refer to the online Science Safety Manual. Because this information may be dated, you should also refer to the SDS to determine this. Any known human carcinogen, suspect human carcinogen, or known animal carcinogen should not be used.
  • Are strong oxidizers used? If so, will they be dilute solutions?
  • Are chemicals considered mutagenic or teratogenic?
  • Can the lab procedure generate significant pressure?
  • Can the lab procedure result in a fire or explosion due to the reactive nature of the chemicals?
  • Does the lab have a fume hood or ventilation? If not, the lab experiments cannot use hazardous chemicals. Use the following guidelines to determine whether the experiment requires the use of a fume hood. As a rule of thumb, use a fume hood or other local ventilation device when working with any appreciably volatile substance with PEL (Permissible Exposure Limit) or TLV (Threshold Limit Value) ofless than 50 ppm (parts per million) or when working with any volatile hazardous chemical (those with vapor pressures above 20 mm Hg). Procedures involving moderately toxic or slightly toxic chemicals (those with PELs TLVs greater than 100 ppm or 500 ppm respectively) may have to be conducted in a fume hood depending on the quantity involved and the rate of evaporation.
  • Does the lab procedure generate significant amounts of hazardous waste?

Please note that on Jan. 10, 2014, all high school principals received an email from the Department of Education informing them at all schools must suspend performing the "rainbow experiment".