New Jersey Administrative Code
Title 7 - ENVIRONMENTAL PROTECTION
Chapter 26D - REMEDIATION STANDARDS
Appendix 5
DEVELOPMENT OF INDOOR AIR REMEDIATION STANDARDS FOR THE VAPOR INTRUSION EXPOSURE PATHWAY
This appendix describes the procedures and equations used by the Department to develop the indoor air remediation standards for the vapor intrusion exposure pathway as contained at N.J.A.C. 7:26D Appendix 1, Tables 7 and 8. This appendix is also used to develop interim indoor air remediation standards for the vapor intrusion exposure pathway pursuant to N.J.A.C. 7:26D-6 and for updating indoor air remediation standards for the vapor intrusion exposure pathway pursuant to N.J.A.C. 7:26D-7.
If the calculated indoor air human health-based criterion for a contaminant is less than the reporting limit, the indoor air remediation standard defaults to the reporting limit.
Equations 1 and 2 below are derived from the USEPA, Regional Screening Levels (RSLs)--Equations (November 2018). A detailed explanation of the derivation of Equations 1 and 2 is contained at N.J.A.C. 7:26D Appendix 12.
Equation 1--Carcinogenic Indoor Air Human Health-Based Criteria
Parameter | Definition | Units | Default |
IAc | Carcinogenic indoor air human healthbased criterion | µg/m3 | Chemical specific |
TR | Target cancer risk | unitless | 1 x 10-6 |
AT | Averaging time | days/year | 365 |
LT | Lifetime | years | 70 |
EF | Exposure frequency | days/year | 350 (Residential) 250 (Nonresidential-indoor worker) |
ED | Exposure duration | years | 26 (Residential) 25 (Nonresidential) |
ET | Exposure time | hours/day | 24 (Residential) 8 (Nonresidential) |
IUR | Inhalation unit risk | (µg/m3)-1 | Chemical specific |
Equation 2--Noncarcinogenic Indoor Air Human Health-Based Criteria
Parameter | Definition | Units | Default |
IAnc | Noncarcinogenic indoor air human healthbased criterion | µg/m3 | Chemical specific |
THQ | Target hazard quotient | unitless | 1 |
AT | Averaging time | days/year | 365 |
ED | Exposure duration | years | 26 (Residential) 25 (Nonresidential) |
EF | Exposure frequency | days/year | 350 (Residential) 250 (Nonresidential-indoor worker) |
ET | Exposure time | hours/day | 24 (Residential) 8 (Nonresidential) |
RfC | Inhalation reference concentration | mg/m3 | Chemical specific |