About TCEQ Development Support Documents (DSDs) for Effects Screening Levels (ESLs) and Air Monitoring Comparison Values (AMCVs)
TCEQ Toxicology Deadlines
Regarding 3 Proposed DSDs
Deadline: August 29, 2014
3 new 24-hour AMCVs and 1 new DSD have been posted!
2 White Papers have been finalized!
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.
Files linked from this page are in Portable Document Format (PDF) 
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WHITE PAPER – TCEQ Guidelines to Develop 24-Hour Inhalation Reference Values
The TCEQ sought public comments on a White Paper on TCEQ Guidelines to Develop 24-Hour Inhalation Reference Values. The document provides guidelines to develop chemical-specific 24-h reference values (ReVs). It is a supplement to the TCEQ Regulatory Guidance-442 (RG-442), TCEQ Guidelines to Develop Toxicity Factors. Reference Values are used as air monitoring comparison values (AMCVs). The 24-hour Guidelines went through an external peer review, as discussed in the Document Description and Intended Use. The TCEQ posted these guidelines for a second public comment period and the document was finalized in June 2014. Please refer to the Guidelines to Develop 24-Hour Inhalation Reference Values to review the final draft. Please also review the TCEQ's Response to Public Comments .
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 Paper for a discussion of the changes.
Current Public Comment Periods
Three Proposed DSDs - Ending August 29, 2014
Chromic Acid Mist Carbon Disulfide Acrolein 24-hour Value
Procedure to Submit Comments
Submit comments by e-mail to tox@tceq.texas.gov or by mail (must be received at the TCEQ no later than the respective comment period end dates) 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
Call: 877-992-8370 (toll free) or 512-239-3900
E-mail: tox@tceq.texas.gov
Write: Texas Commission on Environmental Quality
Toxicology Division, MC 168
P.O. Box 13087
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.