External Scientific Peer Reviews
The TCEQ has prepared draft DSDs that outline the hazard assessment and dose-response processes used to derive health-protective Effects Screening Levels (ESLs) and Unit Risk Factors (URFs) for hexavalent chromium and isoprene. These toxicity values are used in the evaluation of air permit applications and ambient air data and were developed using TCEQ Guidelines to Develop Toxicity Factors (TCEQ 2012).
Toxicology Excellence for Risk Assessment (TERA) organized an expert external peer review of these two DSDs. Technical and Scientific Comments from the public were due to TERA by May 24, 2013 and accepted via email. Comments from the public will be included as an appendix to each final peer review report.
Isoprene (draft dated April 2013)
This peer review will be conducted as a letter review only.
The draft Isoprene DSD includes Section 4.2, which documents the derivation of an inhalation unit risk factor (URF) based on liver carcinoma incidence in mice and air concentrations corresponding to the policy-based 1 in 100,000 excess risk level.
Visit TERA's Isoprene Peer Review Web Page to view the report and for updated information.
Hexavalent Chromium (draft dated March 2013)
This peer review will be conducted as a letter review with a follow-up conference call. The conference call date is still to be determined.
The draft Hexavalent Chromium DSD includes Section 4.2, which documents the derivation of an URF and air concentrations corresponding to the policy-based 1 in 100,000 excess risk level based on lung cancer mortality.
Visit TERA's Hexavalent Chromium Peer Review Web Page to view the report and for updated information.
Sign Up to Receive ESL List, AMCV List, and Other Related Toxicology Announcements
To join the Toxicology Announcement List, please e-mail:
Do not put any information in either the subject or message body.
You will automatically receive an acknowledgment by e-mail informing you that your request has been received; however, you must confirm you want to be placed on the list. To make the confirmation, reply to the message.
Once the list administrator has admitted your email address to the list, you will receive a welcome document.