documents the criteria and information sources that have been
used by the National Institute for Occupational Safety and Health
(NIOSH) to determine immediately dangerous to life or health
concentrations (IDLHs). IDLHs were originally determined for
387 substances in the mid-1970's as part of the Standards Completion
Program (SCP), a joint project by NIOSH and the Occupational
Safety and Health Administration (OSHA), for use in assigning
respiratory protection equipment. NIOSH is currently evaluating
the scientific adequacy of the criteria and procedures used
during the SCP for establishing IDLHs. In the interim, the IDLHs
have been reviewed and, (if appropriate) revised. In this document,
IDLHs are listed with the basis and references for the current
values as well as with the original IDLHs and their documentation
(as paraphrased from the SCP draft technical standards).
is extended to the following individuals from the Division of
Standards Development and Technology Transfer: Crystal L. Ellison
for locating the references and verifying the information used
during the Standards Completion Program to determine the original
IDLHs; Rosmarie T. Hagedorn, Marsha A. Striley, and B. JoAnne
Hamons for typing the numerous drafts of this document; Vanessa
L. Becks for assistance in page design; and Laurence D. Reed,
Ralph D. Zumwalde, Robert W. Mason, and G. Kent Hatfield for
their technical reviews and comments.
Mention of the name of any company or product does not constitute endorsement by the National Institute for Occupational Safety and Health.