Hydrogen Sulfide Regulatory Revisions-July 2001

Hydrogen Sulfide is a colorless gas that is found as a by-product of chemical reactions, such as in sewage treatment. As reviewed in our Right to Know sessions, Hydrogen Sulfide is an asphyxiant, a highly flammable gas (hazard rating of 4) and a dangerous fire hazard. The New Jersey Department of Health and Senior Services Hazardous Substance Fact Sheet (Fact Sheet) for Hydrogen Sulfide has been revised. Our clients may be interested in the following sections of the revised Hydrogen Sulfide Fact Sheet.

1. Workplace Exposure Limits

A. OSHA:	The revised legal airborne PEL is 20 ppm, not to be exceeded at any time.
B. NIOSH:	The recommended airborne exposure limit is 10 ppm, which should not be exceeded at any time.
C. ACGIH:	The recommended airborne exposure limit is 5 ppm, averaged over an 8-hour work shift.

The above exposure limits are for air-levels only. When skin contact also occurs, absorption of Hydrogen Sulfide may lead to overexposure, even though air levels are less than the limits listed above.

2. Personal Protective Equipment

The following text is included in the Respiratory Protection section of the Hydrogen Sulfide NJDHSS Hazardous Substances Fact Sheet:

Where the potential exists for an exposure over 5 ppm, use a NIOSH approved supplied-air respirator with a full face piece operated in a pressure-demand or other positive-pressure mode. Note: This concentration was previously 10 ppm.

3. Immediately Dangerous to Life and Health (IDLH)

Exposure to 100 ppm is immediately dangerous to life and health (IDLH). If the possibility of exposure above 100 ppm exists, use a NIOSH approved self-contained breathing apparatus with a full face piece operated in a pressure-demand or other positive-pressure mode. IDLH was listed as 300 ppm in 1993, and as 800 ppm in 1986.