What Are the Standards and Regulation for Arsenic Exposure?

Upon completion of this section, you will be able to

• describe U.S. standards for arsenic exposure

We know that the toxic effects of arsenic depend on the nature and extent of exposure (dose), particularly the

• concentration of arsenic involved in the exposure,
• frequency of exposure,
• duration of exposure, and
• type of arsenic involved in the exposure.

U.S. government standards for arsenic include a standard for

• air levels of arsenic in the workplace,
• animals used as food, and
• arsenic in drinking water.

The U.S Occupational Safety and Health Administration (OSHA) mandates permissible limits for arsenic occupational exposure.

• The permissible exposure limit for arsenic is no greater than 10 micrograms of inorganic arsenic per cubic meter of air, averaged over any 8 hour period for a 40 hour workweek [OSHA 2001; NIOSH 2005].

The American Conference of Governmental Industrial Hygienists has set a threshold limit value of 10 micrograms per cubic meter/ Arsenic and inorganic compounds as Arsenic [ACGIH 2005] (See Table 4).

The recommended exposure limit set by the National Institute for Occupational Safety and Health (NIOSH) is 2 microgram per cubic meter of air for no more than a 15 minute period, based on classification of arsenic as a potential human carcinogen.

For further information about OSHA standards, see http://www.osha.gov/SLTC/arsenic/index.html

For further information about protection guidelines, contact NIOSH at 1-800-CDC-INFO (1-800-232-4636) or visit the Web site at http://www.cdc.gov/niosh/npg/npgsyn-a.html

Air

The U.S. Environmental Protection Agency (EPA) lists arsenic under authorization of the Clean Air Act as a hazardous air pollutant, defined as a substance that may cause an increased mortality or serious illness in humans after significant exposure [EPA 2007].

• In 1986, EPA promulgated the National Emissions Standards for Hazardous Air Pollutants for three stationary source categories known to emit inorganic arsenic:

1. arsenic plants,
2. glass manufacturing plants, and
3. primary copper smelters [EPA 2007].

• There is no ambient air standard (i.e., no general air pollution limit) for arsenic [EPA 2007].

Drinking Water

EPA has set 10 ppb as the allowable level for arsenic in drinking water (maximum contaminant level). (EPA 2006)

The World Health Organization recommends a provisional drinking water guideline of 10 ppb.

Food

Arsenic is used in some veterinary drugs, including those used to treat animals used for commercial food products.

The U.S. Food and Drug Administration (FDA) has established tolerance levels for arsenic in byproducts of animals treated with veterinary drugs. These permissible levels range from 0.5 ppm in eggs and uncooked edible tissues of chickens and turkeys to 2 ppm in certain uncooked edible byproducts of swine.

Shellfish (especially bivalve mollusks and crustaceans) concentrate arsenic in seawater, but it exists in the organic forms, which have not been shown to produce adverse effects in humans consuming these seafoods. This type of organic arsenic is also rapidly excreted.

Pesticides

The EPA Office of Pesticide Programs (OPP) has restricted the use of inorganic arsenic in pressure treated wood. It has also cancelled all registered uses of inorganic arsenic for non-wood preservative purposes.

For more information on EPA rules and regulations regarding arsenic, see https://www.epa.gov/ttn/atw/hlthef/arsenic.html.

• ACGIH = American Conference of Governmental Industrial Hygienists
• EPA = U.S. Environmental Protection Agency
• FDA = U.S. Food and Drug Administration
• NIOSH = National Institute for Occupational Safety and Health
• OSHA = Occupational Safety and Health Administration
  • TLV/TWA (Threshold Limit Value/Time Weighted Average) = time weighted average concentration for a normal 8 hour workday or 40 hour workweek to which nearly all workers may be repeatedly exposed.
  • PEL (Permissible Exposure Limit) = highest level averaged over an 8 hour workday to which a worker may be exposed.

• Occupational exposure law (OSHA standard) and environmental law (EPA standard) limit workplace airborne exposure and environmental drinking water exposures to arsenic, respectively.