Atrazine, Propazine, Simazine and their Chlorometabolites DACT, DEA and DIA Listed Effective July 15, 2016 as Reproductive Toxicants

On March 27, 2015, the Office of Environmental Health Hazard Assessment (OEHHA) provided notice that atrazine, propazine, simazine, des-ethyl atrazine (DEA), des-isopropyl atrazine (DIA) and 2,4-diamino-6-chloro-s-triazine (DACT)^[1] would be added to the list of chemicals known to the state to cause reproductive toxicity for purposes of Proposition 65^[2] with a delayed effective date due to pending litigation.

The listing of these chemicals was initially to be effective on August 3, 2015. Due to Syngenta Crop Protection’s^[3] legal challenge to the listing, this was later changed several times because of delays in the litigation. Syngenta’s challenge was unsuccessful in the trial court.  Although the case has been appealed, no stay of the listing has been granted. Therefore, atrazine, propazine, simazine, des-ethyl atrazine (DEA), des-isopropyl atrazine (DIA) and 2,4-diamino-6-chloro-s-triazine (DACT) are being added to the Proposition 65 list on July 15, 2016.

In summary, these six chemicals are listed under Proposition 65 effective July 15, 2016 as known to the state to cause reproductive toxicity, as follows:

Chemical	CAS No.	Toxicological Endpoints	Listing Mechanism*
Atrazine	1912-24-9	Developmental toxicity Female reproductive toxicity	AB (US EPA)
Propazine	139-40-2
Simazine	122-34-9
Des-ethyl atrazine (DEA)	6190-65-4
Des-isopropyl atrazine (DIA)	1007-28-9
2,4-Diamino-6-chloro-s-triazine (DACT)	3397-62-4

Chemical Reference

• Atrazine
• Propazine
• Simazine
• Des-ethyl atrazine (DEA)
• Des-isopropyl atrazine (DIA)
• 2,4‑diamino‑6‑chloro-s-triazine (DACT)

Related Notices

• Notice of Proposed Rulemaking - MADLs for Atrazine, Propazine, Simazine, 2,4-Diamino-6-Chloro-S-Triazine (DACT), Des-Ethyl Atrazine (DEA), and Des-Isopropyl Atrazine (DIA)

  Jun 10, 2016
• Change in Listing Date: atrazine, propazine, simazine, des-ethyl atrazine (DEA), des-isopropyl atrazine (DIA) and 2,3-diamino-6-chloro-s-triazine (DACT)

  Jul 31, 2015
• Atrazine, Propazine, Simazine and their Chlorometabolites DACT, DEA And DIA Listed as Reproductive Toxicants

  Mar 24, 2015
• Notice of Intent to List: Atrazine, Propazine, Simazine and their Chlorometabolites DACT, DEA and DIA

  Feb 7, 2014

Footnotes and References

[1] DACT was incorrectly identified as 2,3-diamino-6-chloro-s-triazine (instead of 2,4-diamino-6-chloro-s-triazine) in the Feb. 7, 2014 notice of intent to list the chemical and in the March 24, 2015 notice of listing.

[2] The Safe Drinking Water and Toxic Enforcement Act of 1986, Health and Safety Code section 25249.5 et seq.

[3] Syngenta Crop Protection v. OEHHA (Sacramento Superior Court case #34-2014-800001868)

* Listing mechanism:  AB – “authoritative bodies” mechanism (Title 27, Cal. Code of Regs., section 25306).