An official website of the United States government.

We've made some changes to EPA.gov. If the information you are looking for is not here, you may be able to find it on the EPA Web Archive or the January 19, 2017 Web Snapshot.

Vapor Intrusion

VISL Equations

On this page:

Resident Air Screening Level

Noncarcinogenic

Inhalation
VISL Resident Inhalation Noncancer

Carcinogenic

Inhalation
VISL Resident Inhalation Cancer

Mutagenic

Inhalation
VISL Resident Inhalation Mutagen

Vinyl Chloride

Inhalation
VISL Resident Inhalation Vinyl Chloride

Trichloroethylene

Inhalation
VISL Resident Inhalation Trichloroethylene

  • Trichloroethylene Supporting Equation
    Inhalation
    VISL Trichloroethylene Adjustment

Top of Page

Worker Air Screening Level

Noncarcinogenic

InhalationVISL Worker Inhalation Noncancer

Carcinogenic

InhalationVISL Worker Inhalation Cancer

Top of Page

Groundwater Screening Level

VISL Groundwater Target Screening Level

Top of Page

Soil Gas Screening Level

VISL Soil Gas Target Screening Level

Top of Page

Vapor Intrusion Screening Level Supporting Equations

  • Pure Phase Vapor Concentration
    VISL Pure Phase Vapor Concentration
  • Groundwater Vapor Concentration
    VISL Groundwater Vapor Concentration

Top of Page

Indoor Air Concentration Derived from Soil Gas Concentration

  • Calculated Indoor Air Concentration from Soil Gas
    Vapor Intrusion Calculated Indoor Air Concentration from Soil Gas

Top of Page

Indoor Air Concentration Derived from Groundwater Concentration

  • Calculated Indoor Air Concentration from Groundwater
    Vapor Intrusion Calculated Indoor Air Concentration from Groundwater

Top of Page

Calculation of Risks and Hazards from Indoor Air Concentrations

  • Excess Lifetime Cancer Risk
    VISL Excess Lifetime Cancer Risk Calculation
  • Hazard Quotient
    VISL Hazard Quotient Calculation

Top of Page

Resident Air CDI

Chronic Daily Intake Resident Noncarcinogenic
Vapor Intrusion Chronic Daily Intake Resident Noncarcinogenic

Chronic Daily Intake Resident Carcinogenic
Vapor Intrusion Chronic Daily Intake Resident Carcinogenic

Chronic Daily Intake Resident Mutagenic
Vapor Intrusion Chronic Daily Intake Resident Mutagenic

Chronic Daily Intake Resident Vinyl Chloride
Vapor Intrusion Chronic Daily Intake Resident Vinyl Chloride

Chronic Daily Intake Resident Trichloroethylene
Vapor Intrusion Chronic Daily Intake Resident Trichloroethylene

  • Trichloroethylene Supporting Equation
    Inhalation
    VISL Trichloroethylene Adjustment

Top of Page

Worker Air CDI

Chronic Daily Intake Worker Noncarcinogenic
Vapor Intrusion Chronic Daily Intake Industrial Worker Noncarcinogenic

Chronic Daily Intake Worker Carcinogenic
Vapor Intrusion Chronic Daily Intake Industrial Worker Carcinogenic

Top of Page

Using Units in ppb

  • ppb Unit Conversion
    VISL Conversion to Parts Per Billion

Top of Page

Modifications of Groundwater Temperatures

To Determine Unitless Henry's Law Constant at a Groundwater Temperature of 25° Celsius
VISL Soil Gas Concentration

hprime.gif

To Determine Unitless Henry's Law Constant at a Groundwater Temperature of 25° Celsius
VISL Unitless Henry's Law Conversion

To Determine Vapor Pressure at a Groundwater Temperature other than 25° Celsius
vptgw.gif

To Determine Pure Phase Vapor Concentration at a Groundwater Temperature other than 25° Celsius
visl_vpctgw.gif

Top of Page