The Home page of ILPI's Safety Data Sheet (SDS) Resource, the leader in SDS information since 1995!
The history and philosophy behind this resource.
A curated collection of books and reference materials concerning Safety Data Sheets and closely related topics.
Paste your plain text SDS into the SDS-Demystifier, and it will be converted into a hypertext-enriched document with links to detailed explanations of each key term.
An extensive list of frequently asked questions about Safety Data Sheets including regulations, content, compliance, and more.
A humorous take on Safety Data Sheet jargon. Fill in the blanks on our entry form to generate a personalized Unsafety Data Sheet to share with your coworkers.
Since 1995, we've maintained this massive curated list of the best places to find Safety Data Sheets on the Internet.
You are here! Way more than a glossary, this hypertext-enhanced resource covers hundreds of SDS-related terms and expert knowledge. Each entry includes both the SDS relevance and links to additional authoritative resources.
Archived results of Safety Data Sheet related polls taken by some of our millions of site visitors
The OSHA regulations behind SDS regulations, including the inspection guidelines and over 400 official interpretations letters under the Hazard Communication Standard
Commercial suppliers of SDS authoring and management software as well as cloud compliance services.
Commercial companies that will create SDS's for your specific needs as well as SDS translation companies.
Safety signs, banners, and scoreboards? Get yours at Safety Emporium!
Action levels are used by OSHA and NIOSH to express a health or physical hazard. They indicate the level of a harmful or toxic substance/activity which requires medical surveillance, increased industrial hygiene monitoring, or biological monitoring.
Additional Info
Action levels are generally set at one half of the permissible exposure limit (PEL), but the actual level may vary from standard to standard. The intent is to identify a level at which the vast majority of randomly sampled exposures will be below the PEL. One can not simply apply the 1/2 ratio to each substance because chemicals differ, not all dose/response curves are linear, and not all measurements of exposure have the same accuracy or precision (and can be process-dependent, in fact). Therefore, each one is presumably calculated on the best epidemiological and other known data. For example, the PEL for formaldehyde is 0.75 ppm while its action level is 0.5 ppm (higher than one-half the PEL) despite it being a very strong sensitizer.
For a bit of background on the history of the 1/2 ratio and the statistical considerations that are involved in coming up with an action level, see this very dated (1975) NIOSH Technical Information sheet, HEW Publication No (NIOSH)76-131 titled Exposure Measurement Action Level and Occupational Environmental Variability.
If you are dealing with a substance which has a PEL and you exceed 50% of the PEL or the action limit, you need to take appropriate action to monitor the levels and/or employee health on a regular basis. Consult your industrial hygienist, safety officer or local OSHA compliance (not enforcement) office for assistance (see below for contact information).
Disclaimer: The information contained herein is believed to be true and accurate, however ILPI makes no guarantees concerning the veracity of any statement. Use of any information on this page is at the reader's own risk. ILPI strongly encourages the reader to consult the appropriate local, state and federal agencies concerning the matters discussed herein.