Proposed Regulations: Toxicity Criteria for Human Health Risk Assessment

DTSC Reference Number: R-2016-08
OAL Reference Number: Z-2017-0725-08



The 15-day public comment period for the Toxicity Criteria Regulations (R-2016-08) closed on April 21, 2018. 

Should you have any questions or concerns, feel free to send an email to or call the Regulations Coordinator, Jackie Buttle, at 916-324-8286, or the Project Manager for this rulemaking file, Kevin Depies at 916-255-6547.


Public Workshops

DTSC hosted two informal informal public workshops to explain the proposed rule, and had informal discussions with as well as solicited preliminary input by the public on the proposed rule.  The first workshop was held on August 28, 2017 from 2:00 PM to 4:00 PM at 8800 Cal Center Drive, Sacramento, CA, 95826 in the Board Room. 

The second workshop was held on August 31, 2017 from 2:00 PM to 4:00 PM at 5796 Corporate Avenue, Cypress, California 90630 in the "All-Staff Room". 

 Click Here to view the slideshow presentation that was discussed at both informal workshops.

 Click here to view the webcast video that was broadcast during the public workshop.


Public Hearing

DTSC held a formal APA public hearing on September 20, 2017 from 2:00 PM to 4:00 PM at 8800 Cal Center Drive, Sacramento, California 95826 in the Board Room.  

You can listen to the audio recording of this meeting here.

** If you require written transcript of this audio recording, it can be made available upon request.  Email the request to .

Official Public Hearing Audio Recording

CURRENT Related Documents & Links

During the 15-day public comment period, DTSC welcomes comments and questions pertaining to the modified draft proposed regulation and STD 399; the following documents are available for the 15-day public comment period review, which include the comments received from the 45-day comment period, along with DTSC's responses to those comments:


(The original public notice for the 15-day comment period incorrectly stated that text deleted from the draft proposed regulation is identified with a "double-strikethrough" in the revised draft proposed regulation text.  However, the notice should have instead stated that the text deleted from the draft proposed regulation is identified with a "single-strikethrough" in the revised draft proposed regulation text.  The corrected public notice for the 15-day comment period is available below)





Other Supporting Documents


Supporting Documents for Analytes Listed in Appendix I of the Proposed Regulations

Table of Contents - Analytes

1. Acetaldehyde

2. Ammonia, Boron Trifluoride, Hydrochloric acid,1,1,1-Trichloroethane

3. Arsenic and Arsine

4. Benzene

5. Benzidine, Bis(2-Chloroethyl)ether, Cadmium, 3,3'-Dichlorobenzidine, 1,4-Dioxane, HCH(Mixed Isomers), Hexachlorobenzene, N-Nitroso-di-n-butylamine, and 2,4,6-Trichlorophenol

6. Polynuclear Aromatic Hydrocarbons

7. Beryllium and compounds

8. Bromoform

9. 1,3-Butadiene

10. 2-Butoxyethanol

11. Carbon Tetrachloride

12. Carbonyl Sulfide

13. Chlordane

14. Chromium VI

15. 1,1 Dichloroethylene, Toluene, and Epichlorohydrin

16. 1,3-Dichloropropene (cis- and trans-)

17. Ethylene Dibromide

18. Formaldehyde, Manganese, Mercury, and Mercuric Chloride

19. Hexachlorodibenzo-p-dioxin mixture

20. Lead and compounds

21. Lead Subacetate, 4,4'Methylene-bis(2-chloroaniline), Mirex, 1-Naphthylamine, o-Toluidine

22. Methylene Chloride

23. Methylene diphenyl diisocyanate and Polymeric MDI

24. Nickel and Nickel Compounds

25. Styrene

26. Tetrachloroethene

27. Toluene 2,4 2,6-Diisocyanates

28. Toxaphene

29. Vinyl Chloride



Important historical documents and information


In response to several requests from the public, the Department of Toxic Substances Control (DTSC) has decided to extend the deadline for public comments on the pre‐rulemaking draft regulation - Toxicity Criteria for Human Health Risk Assessments and Cleanup Decisions. DTSC has decided to push the deadline back to Tuesday, January 31, 2017.

The proposed rulemaking on the toxicity criteria for human health risk‐based screening levels, action levels, and remediation goals would add a new chapter to the California Code of Regulations, Title 22, Division 4.5, Environmental Health Standards for the Management of Hazardous Waste.





Documents from 45-Day Comment Period Review:



  • Notice of Proposed Action (NOPA) <-- WITH REVISIONS


  • Draft Proposed Regulation Text