CAL/OSHA PEL Activities: NMP
Barbara Kanegsberg
CAL/OSHA is considering setting the worker permissible exposure limits
(PEL) for n-methyl pyrollidone (NMP) to a low level. These are considerations,
not final decisions. We’re not screaming NMP in a crowded theater;
or shouting that “the PEL’s are falling.” However, we think
you should be aware of and follow the CAL/OSHA activities, because NMP is
used in a number of diverse industrial applications, NMP is being considered
as a replacement for Hazardous Air Pollutants (HAPs) in many pollution prevention
and sustainable process efforts. Cal/OSHA can set PEL’s that are enforceable
throughout California; it is reasonable to expect that California PEL’s
may influence activities throughout the United States.
Adding to available PEL’s
California is working to set state-wide PEL’s, particularly where Federal
OSHA has not set worker exposure levels. According to a document issued by
the California Hazard Evaluation System & Information Service (HESIS),
a department of the California Department of Health Services (DHS), the only
existing US exposure guideline for NMP is an 8-hr Time Weighted Average (TWA)
of 10ppm, recommended by the American Industrial Hygiene Association's Workplace
Environmental Exposure Level (WEEL) committee. NMP eight-hour exposure limits
set by 14 other countries range from 1 ppm to 100 ppm.
Analysis, 1 ppm PEL, TLV for NMP
In a report and analysis of NMP prepared by Julia Quint and presented
at the November 2, 2007 meeting of the Health Expert Advisory Committee
(HEAC)
that is tasked by Cal/OSHA to recommend PEL values, the recommendation
was for a PEL of 1 ppm (TWA) with a skin notation and required biological
monitoring.
The recommendation is based in part on analysis and community risk
assessment by the Office of Environmental Health Hazard Assessment (OEHHA);
and
the 10-fold uncertainty factor used to develop the number includes
an allowance
to protect sensitive population. OEHHA is perhaps most familiar to
you as developing the list used for the Proposition 65 warnings posted
in
businesses and public places throughout California.
It is our understanding that the 1 ppm recommendation is just that – a
recommendation. We would expect to see discussions at one additional meeting
of the HEAC; and there are additional steps to the PEL process.
It is to the credit of Cal/OSHA that the newly-developed PEL process
is transparent and that report templates will make the process
somewhat standardized.
The
NMP report is publicly available and downloadable at the DOSH website.
Please note that California Department of Occupational Safety and
Health (DOSH)
is often referred to as Cal/OSHA.
http://www.dir.ca.gov/dosh/DoshReg/5155Meetings.htm
Additional chemicals; upcoming HEAC meeting
In addition to NMP, other compounds scheduled for near-term consideration
include dichloroacetic acid, hydrogen fluoride, and hydrogen
chloride.
The next meeting of the HEAC is scheduled for January 29, 2008,
in Oakland, CA. The tentative agenda includes toluene, trichloroethylene,
carbon
disulfide, and sulfuric acid.
More about the Cal/OSHA PEL Process
The recently-unveiled Cal/OSHA PEL process has the potential
for efficiency, standardization, and transparency. Toxicological
issues
tend to be
complex. Since the California PEL’s may impact your operation and your workers,
you will find it productive to learn more about the process and perhaps to
provide input.
Additional information
about the development of the Cal/OSHA PEL process and comparisons of approaches
used for worker
and community
safety
can be found in “Green Files,” the newsletter of the Surface Quality
Resource Center (SQRC), volume II, Issues 1 – 3,
2007.
http://www.sqrc.org/Newsletter%201/Newsletter%20page.html
