Overview

In past rule amendments, industries affected by volatile organic compound (VOC) regulations petitioned the South Coast AQMD to exempt compounds from the VOC definition to meet more stringent limits. A limited exemption in Rules 1113 – Architectural Coatings and 1151 - Motor Vehicle and Mobile Equipment Non-Assembly Line Coating Operations was allowed for tBAc in 2006 and 2005, respectively. Proposed amendments to Rules 1168 - Adhesive and Sealant Applications and 1107 - Coating of Metal Parts and Products were put on hold due to toxicity concerns and worker exposure issues involving tBAc.  In August 2015, the Office of Environmental Health Hazard Assessment (OEHHA) released a draft Technical Support Document for Cancer Potency Factors (CPF) for public review that is higher (more carcinogenic) than previously estimated.  This raised concerns regarding the existing limited exemption for tBAc.  During the 2016 amendment to Rule 1113, staff included a resolution to review the existing limited exemption for tBAc and analyze the health risks using the new draft inhalation CPF.  The preliminary draft discusses the regulatory history, health risk analysis, and recommendations for the exemption of tBAc.  The preliminary draft tBAc paper can be accessed in the link below.    

Documents and Presentations

Draft tBAc Assessment White Paper (PDF)
Release Date: April 2017 

Preliminary Draft tBAc Assessment White Paper (PDF) 
Release Date: October 2016

Working Group Presentation
November 1, 2016 (PDF)

Meetings

Stationary Source Meeting  

Teleconference Meeting  

Stationary Source Meeting

Working Group Meeting