More News from the Texas Commission on Environmental Quality (TCEQ)

The list of Effects Screening Levels (ESLs) published by the agency has been updated as of September 30, 2015. This list supersedes the list previously published in March of 2014. The major changes in the new list have been as a consequence of a new TCEQ policy regarding odor-nuisance based ESLs. In the past, odor-based short-term ESLs were set at the lowest published odor threshold from studies using the most appropriate testing procedures. This resulted in some very low ESLs for odorous compounds.

The new policy is contained in the September 1, 2015 agency Position Paper, “Approaches to Derive Odor-Based Values”. According to this publication, odor-based ESLs are now only set for “malodorous” chemicals. In this context, malodorous chemicals are those with very unpleasant, obnoxious, disagreeable, or pungent odors. The agency has published a list of these 170 or so malodorous chemicals. If your company handles chemicals that do not fit in this malodorous category, no short-term odor-based ESL will be set. A short-term health-based ESL will still apply, however.

The Position Paper and the list of malodorous chemicals can be found by following the links below, respectively: