Skip to content. | Skip to navigation

Personal tools


Questions or Comments:
You are here: Home / Toxicology / Development Support Document

About TCEQ Development Support Documents (DSDs) for Effects Screening Levels (ESLs) and Air Monitoring Comparison Values (AMCVs)

A Development Support Document summarizes how chemical-specific toxicity values were derived based on published guidelines (RG-442).

  New Topic Current Public Comment Periods

The public comment period ends on July 17, 2015 for the following:

   Position Paper:


Click here for information on how to submit comments.

Hot InformationThe Toxicology Division is requesting toxicity information through May 22, 2015!


Files linked from this page are in Portable Document Format (PDF) Adobe Acrobat PDF Document. (Help with PDF.)

What is a Development Support Document?

A Development Support Document (DSD) summarizes how chemical-specific toxicity values were derived based on RG-442, Guidelines to Develop Effects Screening Levels, Reference Values, and Unit Risk Factors.

When are Proposed and Final DSDs Published?

A proposed DSD is published at the TCEQ web site for a 60-day public review and comment period. After public comments are received, the TS will address and resolve all relevant issues and make scientifically defensible changes to the DSD and toxicity values, if needed.

The final DSDs with a Response to Comments, if applicable, are then published on the TCEQ website. Registrants on the Toxicology Announcement List will be notified by e-mail when proposed or final DSDs are posted.

Procedure to Submit Comments

New Topic The Toxicology Division is accepting public comments on the Approaches to Derive Odor-Based ValuesAdobe Acrobat PDF Document position paper and the monethanolamineAdobe Acrobat PDF Document, trimethylbenzenesAdobe Acrobat PDF Document, and vinyl acetateAdobe Acrobat PDF Document DSDs.

Submit comments by e-mail to or by mail (must be received at the TCEQ no later than the July 17, 2015) to:

Regular mail:

Toxicology Division, MC 168

Texas Commission on Environmental Quality

P.O. Box 13087

Austin, TX 78711-3087

Mail delivery services:

Toxicology Division, MC 168

Texas Commission on Environmental Quality

12100 Park 35 Circle, Bldg. F

Austin, TX 78753

Contact the TCEQ About DSDs and Fact Sheets

877-992-8370 (toll free) or 512-239-3900


Write: Texas Commission on Environmental Quality

Toxicology Division, MC 168

P.O. Box 13087

Austin, TX 78711-3087

POSITION PAPER – Systematic Review and Evidence Integration

The public comment period on a Position Paper on how to conduct systematic reviews and evidence integration when developing chemical-specific reference values (ReVs), unit risk factors (URFs), reference dose (RfD), slope factors (SFo), and effect screening levels (ESLs) has ended. Public comments have been received and are being addressed by staff toxicologists. Since the TCEQ has developed guidance to develop chemical-specific toxicity factors, there has been an increased interest in developing systematic review guidelines that include clear study inclusion and exclusion criteria and explicit criteria for determining study quality prior to identifying a key study. The position paper was developed to help TCEQ toxicologists conduct systematic reviews and evidence integration and will supplement TCEQ’s 2012 published guidance on deriving toxicity factors (RG-442). This step will help toxicologists document why particular studies were chosen as potential key studies and the reasons for excluding other studies. This step can help with improving transparency, and subsequently help improve risk communication to a wide range of stakeholders.

WHITE PAPER – TCEQ Guidelines to Develop 24-Hour Inhalation Reference Values

WHITE PAPER – Updated Recommendations for Animal-To Human Inhalation Dosimetry

The Toxicology Division (TD) of the Texas Commission on Environmental Quality (TCEQ) amended Section 3.9.1, Default Dosimetry Adjustments for Gases in the October 2012 regulatory guidance document, TCEQ Guidelines to Develop Toxicity Factors (RG-442). This section was updated to include information on animal-to-human inhalation gas dosimetric adjustments based on recommendations in Advances in Inhalation Gas Dosimetry for Derivation of a Reference Concentration (RfC) and Use in Risk Assessment (USEPA 2012, EPA/600/R-12/044). Please refer to the White PaperAdobe Acrobat PDF Document for a discussion of the changes.

Sign Up to Receive ESL List, AMCV List, and Other Related Toxicology Announcements

For instructions on how to join the Toxicology Announcement List, click here.