Notice of Intent to List DDE and Nitrobenzene

The California Environmental Protection Agency’s Office of Environmental Health Hazard Assessment (OEHHA) intends to list the chemicals 1-dichloro-2,2-bis(p-chlorophenyl) ethylene (DDE) and nitrobenzene as known to the State to cause reproductive toxicity under the Safe Drinking Water and Toxic Enforcement Act of 1986. This action is being taken under the authoritative bodies listing mechanism.

OEHHA requested relevant information related to the possible listing of DDE and nitrobenzene in a notice published in the California Regulatory Notice Register on October 30, 2009 (Register 2009, No. 44 Z). OEHHA received no public comments.

Background on listing via the authoritative bodies mechanism:  A chemical must be listed under the Proposition 65 regulations when two conditions are met:

1. An authoritative body formally identifies the chemical as causing reproductive toxicity (Section 25306(d)).
2. The evidence considered by the authoritative body meets the sufficiency criteria contained in the regulations (Section 25306(g)).

However, the chemical is not listed if scientifically valid data which were not considered by the authoritative body clearly establish that the sufficiency of evidence criteria were not met (Section 25306 (h)).The U.S. Environmental Protection Agency (U.S. EPA) is one of several institutions designated as authoritative for the identification of chemicals as causing reproductive toxicity (Section 25306(l)).

OEHHA is the lead agency for Proposition 65 implementation. After an authoritative body has made a determination about a chemical, OEHHA evaluates whether listing under Proposition 65 is required using the criteria contained in the regulations.

OEHHA’s determination: DDE and nitrobenzene each meet the criteria for listing as known to the State to cause reproductive toxicity under Proposition 65, based on findings of the U.S. Environmental Protection Agency (U.S. EPA, 2008; U.S. EPA 2009).

Formal identification and sufficiency of evidence for DDE: In 2008, the U.S. EPA published a report on DDE (U.S. EPA, 2008). This report concludes that the chemical causes developmental and male reproductive toxicity, and satisfies the formal identification and sufficiency of evidence criteria in the Proposition 65 regulations.

OEHHA is relying on the U.S. EPA’s conclusions in the report that DDE causes reproductive toxicity. The U.S. EPA report concludes:

“DDE has been found to be an antiandrogenic compound, which may explain a number of reproductive and developmental effects seen in male rats exposed to DDE at various ages.”

“Observed effects in the male animals include reduced anogenital distance and retention of thoracic nipples in pups exposed during gestation and lactation; delayed puberty in rats exposed either during juvenile development or at very high doses during gestation and lactation; and reduced accessory sex organ weights in exposed adult males.”

“[A]nimal studies also reveal susceptibility to DDE during development, particularly in males. In rats, exposure to 100 mg/kg/day during gestation resulted in a significant decrease in ventral prostate weight in males at 15 months of age and a decrease in weights of glans penis, ventral prostate, and epididymis at 10 months old; reduced anogenital distance and increased mean number of retained nipples also were observed in the newborns. Anogenital distance at birth was reduced in male rat pups exposed transplacentally to 100 mg/kg/day during gestational (sic) (and also unquantified pup exposure during lactation); the animals also had retained thoracic nipples on postnatal day 13 and a significant delay in the onset of puberty was reported.”

Based on the U.S. EPA report and the references cited in the report, the evidence is sufficient for listing by the authoritative bodies mechanism.

Formal identification and sufficiency of evidence for nitrobenzene: In 2009, the U.S. EPA published a report on nitrobenzene (U.S. EPA, 2009). This report concludes that the chemical causes male reproductive toxicity, which satisfies the formal identification and sufficiency of evidence criteria in the Proposition 65 regulations.

OEHHA is relying on the U.S. EPA’s discussion of data and conclusions in the report that nitrobenzene causes reproductive toxicity. The U.S. EPA report concludes:

“In male rats (F344/N and CD) and mice (B6C3F1), nitrobenzene exposure via the inhalation and oral routes has been shown to cause testicular atrophy, including a dramatic decrease in sperm count with ensuing loss of fertility.”

“In rodents… nitrobenzene is a moderately effective male reproductive toxicant.”

There “is strong evidence for nitrobenzene to act as a male reproductive toxicant…”

Thus, the U.S. EPA (2009) has formally identified nitrobenzene as causing male reproductive toxicity in rodents.

Request for comments: OEHHA is committed to public participation in its implementation of Proposition 65. OEHHA wants to ensure that its regulatory decisions are based on a thorough consideration of all relevant information. OEHHA is requesting comments as to whether these two chemicals meet the criteria set forth in the Proposition 65 regulations for authoritative bodies listings. In order to be considered, comments must be received by OEHHA by 5:00 p.m. on Monday, March 1, 2010. We encourage you to submit comments in electronic form, rather than in paper form. Comments transmitted by e-mail should be addressed to sam.delson@oehha.ca.gov. Comments submitted in paper form may be mailed or delivered in person in triplicate, or faxed, to the addresses below:

Mailing Address:    
Sam Delson
Office of Environmental Health Hazard Assessment
P.O. Box 4010, MS-19B
Sacramento, California 95812-4010

Fax: (916) 323-8803
Street Address: 1001 I Street
Sacramento, California 95814

If you have any questions, please contact Sam Delson at sam.delson@oehha.ca.gov or at (916) 445-6900

Chemical Reference

• DDE (Dichlorodiphenyldichloroethylene)
• Nitrobenzene

Related Notices

• Request for Relevant Information on Chemicals Being Considered for Listing by the Authoritative Bodies Mechanism: DDE and Nitrobenzene

  Oct 30, 2009
• Chemicals Listed as Known to the State to Cause Reproductive Toxicity: 1,1-Dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE) (CAS No. 72-55-9) and Nitrobenzene (CAS No. 98-95-3)

  Mar 26, 2010