Toxic Chemicals Hide Behind "Inert" Labels

The report, "Worst Kept Secrets: Toxic Inert Ingredients in Pesticides," documents the hazards of so-called "inert" ingredients, over 2,500 substances that are added to pesticides but are not named on product labels. U.S. regulatory agencies have few requirements for testing toxicological or ecological effects of inerts. Despite this lack of data, the new report shows that over 25 percent of the chemicals used as "inerts" actually have been identified as hazardous.

Inerts pose a wide variety of hazards, according to NCAP. Almost 400 inert ingredients are or have been used as active ingredients in pesticides. In addition, 209 are considered hazardous air or water pollutants, 21 have been classified as carcinogens, and 127 are occupational hazards. Many have been identified by more than one statute or agency.

The report lists the following examples of what it calls active inerts -- ingredients that are or have been registered in the U.S. for use as active ingredients in some pesticide products, but are also listed in other products as as inerts:

• Chlorothalonil, which has been classified as a probable human carcinogen by a U.S. EPA Scientific Advisory Panel

• Coal tar, a known human carcinogen listed by the International Agency for Research on Cancer

• Chloropicrin, a severe respiratory tract irritant and listed by U.S. EPA as a Restricted Use Pesticide

As another example, the "inert" ingredient naphthalene is an active ingredient in 16 currently registered products, primarily moth repellents. It is also cleared for use as an inert and is considered an "inert of unknown toxicity" by the EPA, despite a 1989 toxicological profile of the chemical.

The most frequent manifestation of naphthalene poisoning is hemolytic anemia (destruction of red blood cells), which can lead to varying degrees of jaundice and liver enlargement. In children, severe jaundice resulting from naphthalene-induced hemolysis can result in permanent neurological damage, motor disturbances, convulsions and death. Naphthalene is also classified as one of the 100 substances most commonly found at Superfund sites that pose "the most significant potential threat to human health due to their known and suspected toxicity to humans."

NCAP has filed a number of formal requests with U.S. EPA under the Freedom of Information Act in an attempt to find out how many pesticide products contain certain known or suspected carcinogens, active inerts and/or endocrine disruptors. Many of the requests are still being processed; however, preliminary findings indicate that hazardous inerts are sometimes widely used in pesticide products. For example, cristobalite, a known carcinogen (according to the International Agency for Research on Cancer), is an inert ingredient in over 1,500 pesticide products.

NCAP's report calls for full label disclosure of all ingredients in pesticide products. Consumers and workers have a right to easy access to such information so that they can make informed decisions and better protect themselves. NCAP also recommends that mixtures of active and inert ingredients found in pesticide products be assessed for a wide range of effects including neurotoxicity, carcinogenicity, teratogenicity, adverse reproductive effects and mutagenicity.

The full NCAP report can be obtained via the Internet in PDF format.