Within the definition of hazardous substances, the OSHA Laboratory Standard includes a subcategory called “particularly hazardous substances”. These are:
Substances with High Acute Toxicity (Appendix III)
1) a chemical with an oral LD50 equal or less than 50 mg/kg,
2) a chemical with a dermal LD50 equal or less than 200 mg/kg when administered
by continuous contact for 24 hours,
3) a chemical with an LC50 equal or less than 200 ppm by volume or 2 mg/L of
mist, fume or dust over 1 hour of inhalation.
Carcinogens (Appendix III)
1) regulated carcinogens listed in subpart Z of the OSHA standard.
2) listed as “known to be carcinogens” in the Annual Report on Carcinogens
published by the National Toxicology Program
3) a Group 1 carcinogen “carcinogenic to humans” as well as group 2A and 2B
“reasonably anticipated to be carcinogens” listed by the International Agency for
Research on Cancer, IARC.
Reproductive Toxins (Appendix III)
1) mutagens or substances causing chromosomal damage
2) teratogens or substances having an effect on a fetus
A few chemicals meeting the definition of a particularly hazardous chemical are used in the instructional labs. When this occurs, in addition to following the usual lab rules, the following procedures should be used.
In the event that a student worker is required to handle a particularly hazardous chemical each of the applicable requirements listed above will be followed with the addition provision that the work may only be done at the direction of and with the direct supervision of the laboratory manager or a chemistry faculty member.