EPA’s November 2002 Draft Guidance For Evaluating the Vapor Intrusion to Indoor Air Pathway from Groundwater and Soils, 67 Fed. Rg. 71,169 (Draft Guidance), represented EPA’s first significant attempt to address concerns about vapor intrusion – the process whereby vapors emanating from contaminants at surface soils or groundwater can make their way into buildings. EPA noted in its Draft Guidance that it “[was] not expect[ed] to be used for settings that are primarily occupational.” Draft Guidance at 3. It is agreed that “OSHA [will] generally take the lead role in assessing occupational exposures.” Id. This stance by EPA had also been expressed in EPA’s Environmental Indicators—Frequent Questions document.
Although the Draft Guidance appeared to take a clear stance on the EPA/OSHA jurisdictional issue, the reception it received from regional EPA officials and others was mixed. Some OSHA officials took the position that OSHA’s authority to regulate vapor intrusion was limited to instances in which the contamination originated from chemicals actually used in the workplace. And, many EPA officials expressed dissatisfaction with the Draft Guidance position and suggested that, since OSHA indoor air concentrations levels are less strict than EPA’s, they would continue to push for EPA to take the lead role in regulating workplace air quality. Some state agencies embraced the Draft Guidance position that OSHA requirements would generally govern the workplace, but other states sided with the regional officials who have pushed EPA to take a more active role in addressing workplace air quality.
The EPA/OSHA jurisdiction conflict continues and remains the subject of strong debate. This is reflected in EPA’s February 2012 Superfund Vapor Intrusion Frequently Asked Questions document, which takes the position that risk assessors should generally not use the OSHA standards when evaluating risks from vapor intrusion if the contaminants of concern are not used in the workplace. Whether the source of vapor intrusion is relevant to the issue of which regulatory agency has the authority and the necessary expertise to address the vapor intrusion issue may be subject to debate. It would appear that it is the nature of the workplace environment itself that ought to be determinative.
EPA’s recent guidances for vapor intrusion regarding hazardous substances and petroleum products do not directly address the issue of separate standards for workplace and non-workplace settings. Therefore, the EPA/OSHA jurisdictional conflict discussed some years ago in various articles by this author remains unresolved and subject to debate.