U.S. EPA Reclassifies Six Chemicals as Less Toxic

WASHINGTON, DC, November 19, 2004 (ENS) - At the request of the chemical industry, one chemical has been removed from the federal list of air toxics, and five others have been reclassified as less harmful than previously thought, the U.S. Environmental Protection Agency (EPA) said Thursday. The agency says the move will "create incentives for industry to use solvents that are less toxic and may help decrease the formation of ground level ozone or smog."

The solvent ethylene glycol mono-butyl ether (EGBE) has been removed from the list of hazardous air pollutants, but it remains regulated as a volative organic compound (VOC) and will continue to be reported in the Toxics Release Inventory.

The chemical t-butyl acetate (TBAC) and four others have been exempted from control as volatile organic compounds (VOCs).

EGBE is used in hydraulic fluids and in water-based coatings for various industries including metal can manufacturers. Frequently referred to as butyl, it is also used in varnishes, vinyl and acrylic paints, and as a solvent for varnishes, enamels, spray lacquers, dry cleaning compounds, textiles and cosmetics.

EGBE is sometimes formulated into water based cleaners, degreasers and wax and finish strippers.

In 1997, the EPA received a petition in 1997 from the American Chemistry Council to delist EGBE. After two analyses, the agency says it determined that outdoor use of the chemical would not be harmful to humans or the environment.

"After extensively reviewing the levels of EGBE in the air and the health and environmental impacts associated with those levels, EPA has concluded that potential outdoor exposures to EGBE may not reasonably be anticipated to cause human health or environmental problems," the agency said in a statement Thursday.

The agency admits that "EGBE use and, therefore, emissions may increase as a result of this action," it creates incentives for industry "to use EGBE instead of other more toxic solvents."

Smog is a big problem for cities like Houston, Texas. (Photo courtesy GHASP)

EGBE has been shown to be toxic to liver, kidneys, lungs and red blood cells, according to a report given to the American Occupational Health Conference, in the spring of 1994, by Lawrence W. Raymond, M.D., East Carolina University School of Medicine. The report says seven floor care workers reported nausea, severe eye and upper respiratory irritation when exposed to wax strippers containing EGBE.

The Material Safety Data Sheet for EGBE states, "Acute effects are narcosis and irritation to eyes and skin ... Chronic effects are blood effects and injury to liver and kidney."

In 1990, the National Institute for Occupational Safety and Health (NIOSH) recommended a standard for exposure to EGBE on the job. NIOSH is an agency of the Centers for Disease Control (CDC).

NIOSH said animal studies "clearly demonstrated" the "dose-related adverse effects" of EGBE on the central nervous system, the blood, the kidneys, and the liver. The agency recommended the limit for air or inhalation exposure to EGBE at five parts per million (ppm).

EGBE is found in spray lacquers and paints. (Photo courtesy NATO)

But oxyethanol does not seem to cause mutations. No studies were found that tested either 2-butoxyethanol or 2-butoxyethanol acetate for causing cancer in animals.

TBAC is a chemical that is used to make pharmaceuticals and pesticides, and it also can be used as a solvent.

In 1997, the EPA received a petition from Lyondell Chemical, formerly ARCO Chemical, asking that TBAC be excluded from the definition - and the level of regulation - of a volatile organic compound.

On Thursday, the agency complied, announcing that TBAC meets the criteria used to define a compound as “negligibly reactive.”

Exclusion of this compound as a VOC "will help states focus on controlling emissions of those pollutants that are demonstrated to be ozone precursors," the EPA said.

The agency said that "a number of manufacturers of paints, inks, and adhesives have indicated that if TBAC were excluded from regulation as a VOC, they would use it in their products in place of other compounds that are as much as 20 to 30 times more likely to form ground level ozone, or smog."

These substitutions will help decrease smog, the EPA said.

But the agency used a different criteria for evaluating whether TBAC is "negligibly reactive" than it has ever used before.

When the EPA determines that a chemical is less reactive than the baseline chemical ethane, the agency considers it "negligibly reactive" and can exclude it from the definition of a volatile organical compound. If the chemical is not classed as a VOC it can avoid the stricter regulations applied to VOCs.

Reactivities can be compared on either a per-gram - or weight - basis, or on a per-mole - or mass - basis. TBAC is less reactive than ethane on a per-gram basis, but more reactive on a per-mole basis.

The EPA usually evaluates substances on a per-mole basis, but the agency chose to evaluate TBAC on the per-gram basis, "since grams, rather than moles, is the unit used in regulations dealing with VOC emissions," the agency said.

"This is the only case in which EPA has classified a compound as negligibly reactive solely on the per-gram basis," it explained in the proposed rule.

TBAC, tert-Butyl acetate, is a flammable, colorless liquid with a fruity odor. On the job, the Occupational Safety and Health Administration (OSHA) says that exposure to tert-butyl acetate causes eye, skin, and respiratory irritation in workers and may act as a central nervous system depressant at high concentrations.

Plane sprays pesticide on crops. (Photo courtesy FWS)

The EPA also is excluding four chemicals - HFE-7000, HFE-7500, HFC 227ea, and methyl formate - from control as volatile organic compounds.

Used as refrigerants, fire suppressants, and propellants, the agency said these chemicals "contribute little or nothing to ground level ozone formation."

These four compounds are preferable substitutes for CFCs and HCFCs, which contribute to the destruction of Earth’s stratospheric ozone layer. This protective layer which keeps out harmful ultra-violet rays from the Sun, exists above the ground level atmospheric level that can be contaminated with smog.

In a separate action, EPA is taking the pesticide phosmet off the Extremely Hazardous Substance list under the Emergency Planning and Community Right to Know Act (EPCRA). That means that state emergency response commissions and local emergency planning committee will no longer have to include phosmet in their emergency plans.

Phosmet is a non-systemic organophosphate insecticide used for agricultural crop protection of fruit, nut and certain field crops that will still be classed as a “hazardous chemical," except," said the EPA, "when it is used in routine agricultural operations, such as a pesticide applied on crops."

Facilities that process or distribute phosmet would still be have to submit inventory and material safety data sheets if they have phosmet present in amounts equal to or greater than 10,000 pounds.

The EPA also will continue to regulate phosmet under the agency’s existing pesticide regulatory program.

To learn more:

EBGE: Copies of the original petition and its supporting information are available for public inspection and copying at the following address: U.S. Environmental Protection Agency, Air and Radiation Docket and Information Center (6102), 1200 Pennsylvania Ave. N.W., Washington, D.C. 20460. For further information including the final rule and the Federal Register notice once published, go to EPA’s web site at: http://www.epa.gov/airlinks/airlinks1.html .

TBAC: Interested parties can download the rule from the EPA’s web site on the Internet under “recent actions” at the following address: http://www.epa.gov/airlinks/airlinks1.html .

Additional Compounds: Interested parties can download the final rule from EPA’s web site on the Internet under “recent actions” at the following address: http://www.epa.gov/airlinks/airlinks1.html .

Phosmet: For more information on phosmet, go to: http://www.epa.gov/pesticides/op/phosmet.htm . For information on the Emergency Planning and Community Right to Know Act, go to: http://yosemite.epa.gov/oswer/ceppoweb.nsf/content/epcraOverview.htm .