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TCEQ Toxicology

Toxicology is used to help the TCEQ make scientifically sound decisions when developing environmental regulation & policy.

New Information A new public comment period has begun for the MDI and HDI, All Isomers, DSD

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Mission Statement:

The Toxicology Division (TD) helps the Texas Commission on Environmental Quality (TCEQ) make scientifically sound decisions by applying toxicological principles when evaluating environmental data, issuing authorizations, developing environmental regulations and making policy decisions.

TCEQ toxicologists identify chemical hazards, evaluate potential exposures, assess human health risks and communicate risk to the general public and stakeholders

What Is Toxicology?

Toxicology is the study of the adverse effects of chemicals on living organisms. A toxicologist is trained to examine the nature of those effects and assess the probability of their occurrence.

Toxicology is used to help the TCEQ make scientifically sound decisions when developing environmental regulations and policy. TCEQ toxicologists help by identifying chemical hazards, evaluating potential exposures, and assessing risks.

What Do TCEQ Toxicologists Do?

TCEQ toxicologists provide toxicological support for a broad range of agency activities. They assist with stakeholder meetings and drafting rules, as well as making technical recommendations regarding agency permitting, monitoring, and enforcement.

  • Conduct the toxicological evaluations of air permit applications;
  • Develop toxicity factors such as ESLs and AMCVs;
  • Evaluate environmental data collected from the air, water, and soil;
  • Evaluate ambient air monitoring data;
  • Contribute toxicological expertise to agency enforcement and emergency-response activities;
  • Coordinate all agency activities that assess risks to human health;
  • Notify private drinking-water well owners of potential groundwater contamination as required by legislation in Texas Water Code 26.408 also known as House Bill 3030;
  • Stay abreast of environmental-health issues and initiatives emerging nationally; and
  • Review Baseline Risk Assessments and various other remediation-related documents submitted under the Texas Risk Reduction Program and the Risk Reduction Rules for state and federal Superfund sites.

In all areas of responsibility, the division strives to ensure consistency of reviews across the agency.

TCEQ Toxicity Factor Database

The Toxicity Factor Database is now a part of Texas Air Monitoring Information System (TAMIS) database. This database is a one-stop-shop for information about all toxicity factors developed by the TCEQ. If you previously used Excel spreadsheets to access the toxicity factors, you will now access them via the TAMIS database.

The TAMIS database includes not only Effects Screening Levels (ESLs), but also Air Monitoring Comparison Values (AMCVs) and their supporting documentation. The TCEQ created the database in order to reduce errors, improve database structure, provide more information and detail to our customers, and allow more dynamic and efficient data entry.

Special Notations for the Toxicity Factor Database ESLs:
This interoffice memorandum Adobe Acrobat PDF Document provides important information (notations and exceptions) to users on use of ESLs in air permitting. Exceptions provided in the document include how to evaluate a compound designated with PM, as well as exceptions to the 1-hr averaging period. This memorandum was previously provided with the ESL Published Lists under the Cover Memo tab. With the new Toxicity Factor Database, this memorandum will now be housed here for reference.

Learn more about the Toxicity Factor Database and query the Toxicity Factor Database to search for ESLs and AMCVs.

Toxicity Factor Database User Guide

Air Monitoring

Air Monitoring Comparison Values (AMCVs)

Air Permitting

Effects Screening Levels (ESLs)

Air Pollutant Watch List (APWL)

Common Questions and Toxicology Responses

Development Support Documents (DSDs)

Federal Topics

Guidance Documents, Positions Paper, and White Papers

Perfluoro Compounds

Toxicological evaluation of perfluoro compounds (e.g., PFOS, PFOA) Adobe Acrobat PDF Document

Research Projects

Scientific Journal Articles

A bibliography of papers by TCEQ toxicologists that have appeared in scientific journals.

Toxicity Data Requests

Learn How To Submit Toxicity Data and what chemicals we are seeking toxicity data on.