Ohio environmental professionals should now use the Voluntary Action Program standards that took effect on 16 February 2025.
The update revised Ohio Administrative Code Rule 3745-300-08 and its chemical-specific tables. It replaced the previous version, which had been effective since 17 October 2019. The standards apply to voluntary investigations and cleanups involving hazardous substances or petroleum releases.
Key takeaways
- The latest Ohio VAP generic numerical standards took effect on 16 February 2025, replacing the version effective since October 2019.
- The standards cover hundreds of chemicals across soil, indoor air and potable groundwater, with other provisions for petroleum, surface water and sediment.
- The main risk targets remain 1 × 10⁻⁵ excess lifetime cancer risk and a hazard index of 1 for a single chemical.
- The generic direct-contact soil standard for lead is now 200 mg/kg for residential land use, commercial land use with high-frequency child exposure, and construction activities.
- Many chemical-specific values changed following updates to toxicity information and exposure inputs.
- Where a construction-worker soil standard is lower than its calculated residential value, Ohio EPA uses the lower value as the unrestricted residential standard.
- The proposed removal of the 0.5 fraction-contaminated factor did not proceed. Ohio EPA retained it in the final direct-contact soil calculations.
- Multiple chemicals and complete exposure pathways may require cumulative risk and hazard adjustments.
- Supplemental criteria are not automatically generic standards. Some may only be used as part of a property-specific risk assessment.
- Professionals should replace older screening tables and confirm the correct chemical, medium, land use and exposure scenario before assessing compliance.
The latest levels at a glance
Ohio’s VAP does not establish one cleanup level. It provides hundreds of chemical-specific values for different environmental media, land uses and exposure scenarios.
The current framework includes:
- Direct-contact soil standards in milligrams per kilogram (mg/kg) for residential, restricted residential, commercial or industrial, high-frequency child-exposure, and construction settings.
- Indoor-air standards in micrograms per cubic metre (µg/m³) for residential, commercial or industrial, and construction scenarios.
- Unrestricted potable groundwater standards in micrograms per litre (µg/L).
- Surface-water criteria linked to Ohio’s water-quality rules.
- Sediment standards based on the applicable soil, surface-water and ecological exposure pathways.
- Petroleum standards established under Ohio’s underground storage tank rules.
The complete chemical-specific values are published in Appendix A to Rule 3745-300-08.
Headline risk levels
For most hazardous substances, the generic standards use:
- A 1 × 10⁻⁵ excess lifetime cancer risk for a single carcinogenic chemical.
- A hazard index of 1 for a single non-carcinogenic chemical.
Where several chemicals or exposure pathways are present, cumulative risk and hazard calculations are required. This means a concentration below its individual chemical standard may not be sufficient by itself to demonstrate compliance.
These assumptions, exceptions and cumulative-adjustment procedures are set out in the current version of Rule 3745-300-08.
Soil lead is now 200 mg/kg in key exposure settings
The most prominent individual change is the generic direct-contact soil standard for lead.
The current level is 200 mg/kg for:
- Residential land use.
- Commercial land use with high-frequency child exposure.
- Construction activities.
Ohio EPA adopted this value in response to the US EPA’s January 2024 residential soil lead guidance. The agency also corrected the lead footnotes in the four direct-contact soil tables. Lead is treated separately from the usual carcinogenic and non-carcinogenic calculations and is not included in the cumulative risk adjustment.
The commercial or industrial soil value remains scenario-dependent. Professionals should select the correct table rather than apply the 200 mg/kg value to every commercial property.
Ohio EPA explains the lead decision in its November 2024 response to comments.
What else changed?
Many chemical-specific values were recalculated
Ohio EPA updated the inputs used to derive the generic numerical standards, including toxicity information and exposure assumptions. As a result, values changed for numerous substances across the soil, indoor-air and groundwater tables.
For example, the agency confirmed that the construction standards for 1,1-dichloroethylene and fluorene changed because of updated sub-chronic toxicity values.
Because the revision is broader than a short list of contaminants, professionals should not rely on values copied from reports, templates or databases based on the 2019 tables.
Residential soil standards were corrected
Ohio EPA’s approach is that an unrestricted residential standard should also protect people carrying out construction work. Where the calculated construction-worker standard is lower than the residential value, the lower construction value is therefore used as the residential standard.
During its review, the agency identified errors in draft residential values and corrected Table I of Appendix A. This change affects several substances for which construction exposure produces the more restrictive result.
The 0.5 fraction-contaminated assumption was retained
Ohio EPA initially considered removing the 0.5 fraction-contaminated factor from its direct-contact soil calculations. Following industry feedback about the practical and economic effects, the agency retained the factor.
This is important because removing it would have made many direct-contact soil values more restrictive. The final standards therefore do not include that proposed change.
Supplemental criteria are not the same as generic standards
Ohio EPA confirmed that supplemental criteria would continue to be available through its Chemical Information Database and Applicable Regulatory Standards system, including soil criteria for thallium and indoor-air criteria for cis- and trans-1,2-dichloroethylene.
These supplemental values may support a property-specific risk assessment under Rule 3745-300-09. They should not automatically be treated as generic numerical standards.
Petroleum continues to follow separate rules
For petroleum releases, Rule 3745-300-08 points users to standards established under Ohio’s underground storage tank regulatory framework. A property-specific petroleum standard may also be developed under Rule 3745-300-09.
Practitioners should therefore avoid applying the hazardous-substance tables to petroleum without first checking the petroleum-specific provisions.
What environmental professionals should do now
For current or reopened projects:
- Confirm that screening tables, field programs and reporting templates use the standards effective 16 February 2025.
- Recheck lead against the applicable land-use and exposure scenario.
- Review chemicals affected by revised toxicity or exposure inputs instead of assuming that a 2019 value remains valid.
- Apply cumulative chemical and pathway adjustments where required.
- Distinguish generic standards from supplemental or property-specific criteria.
- Check whether petroleum, surface-water, sediment or ecological pathways require standards from another Ohio rule.
Generic standards can only be used when the property’s expected land use and exposure pattern match the assumptions used to derive them. Otherwise, a property-specific risk assessment may be required under Rule 3745-300-09.
Keeping standards current in ESdat
ESdat has recently compiled a range of updated environmental standards across North America, Europe and Australia.
These updates allow users to apply current guideline values, automate compliance monitoring, and incorporate the latest standards into reporting and decision-making workflows in ESdat.
See the available standards at ESdat Environmental Standards.
Frequently asked questions
When were the Ohio VAP standards last updated?
The current version of Rule 3745-300-08 took effect on 16 February 2025. It replaced the version effective from 17 October 2019.
Where can I find the latest chemical-specific levels?
The complete values are in Appendix A to Rule 3745-300-08. The appendix contains separate tables for direct-contact soil, indoor air and unrestricted potable groundwater.
Is there one Ohio VAP cleanup level for each chemical?
Not necessarily. A chemical may have different values depending on:
- The environmental medium.
- The land-use category.
- The exposed population.
- Whether the effect is carcinogenic or non-carcinogenic.
- The number of chemicals and exposure pathways present.
- Whether a generic or property-specific assessment is used.
Selecting a number without confirming its scenario can produce an incorrect compliance result.
What is the current Ohio VAP soil standard for lead?
The generic direct-contact soil standard is 200 mg/kg for residential land use, commercial land use with high-frequency child exposure, and construction activities.
Professionals should consult the applicable table for other commercial or industrial exposure scenarios. Ohio EPA’s reasoning is explained in its November 2024 response to comments.
Do the generic standards function as initial screening levels?
They can be used to demonstrate compliance when the property’s land use and exposure conditions match the assumptions used to derive them. However, the VAP does not allow associated chemicals of concern to be removed from further consideration simply because they fall below an initial screening threshold. Applicable cumulative assessments must still be completed.
Must cumulative risk be assessed when several chemicals are present?
Generally, yes. Where several chemicals of concern occur within an identified area, their carcinogenic risks and non-carcinogenic hazards must be adjusted and combined as required by the rule.
Risk may also need to be summed across complete exposure pathways affecting the same receptor population. Regulatory values based on separate criteria, such as certain maximum contaminant levels, may be treated differently.
Can residential soil standards be assumed to protect construction workers?
The current tables are designed so that the unrestricted residential standard is not less protective than the construction standard. Where the construction-worker value is lower, Ohio EPA uses that lower value as the residential standard.
Professionals should still assess construction activities separately where required, particularly when site conditions or planned work do not match the assumptions behind the generic value.
Are the standards automatically applicable to petroleum releases?
No. Petroleum releases follow standards established under Ohio’s underground storage tank rules. Rule 3745-300-08 refers users to that framework, although property-specific petroleum standards may be developed under Rule 3745-300-09.
What if a chemical has no generic numerical standard?
A property-specific risk assessment may be required. Supplemental criteria may also be available, but their status and permitted use should be confirmed before they are treated as applicable standards.
Can an older report still rely on the 2019 values?
A report’s regulatory basis should reflect the rules applicable to the project and decision date. For current or reopened assessments, professionals should check the 2025 standards and document which rule version was used. Older values should not be carried forward without review.
Glossary
Applicable standard: The concentration or other requirement that must be met for a particular chemical, environmental medium, exposure pathway and property condition.
Carcinogen: A substance capable of causing cancer. Most single-chemical carcinogenic VAP standards are based on an excess lifetime cancer risk of 1 × 10⁻⁵.
Chemical of concern (COC): A hazardous substance or petroleum constituent associated with a release that must be evaluated under the VAP.
Complete exposure pathway: A route through which a chemical can travel from its source to a person or ecological receptor. A pathway generally needs a source, transport mechanism, exposure point and receptor.
Cumulative risk adjustment: The process of combining risks or hazards from several chemicals, or from several complete exposure pathways affecting the same receptor.
Direct-contact soil standard: A soil concentration developed to protect people from exposure through soil ingestion, skin contact, and inhalation of soil-derived vapours or particles.
Exposure scenario: The combination of land use, activity patterns, exposure frequency, duration and receptor characteristics used to calculate a standard.
Exposure unit: A defined area over which exposure is evaluated during a property-specific risk assessment.
Fraction contaminated: The assumed portion of the exposure area affected by contamination. Ohio EPA retained a factor of 0.5 in its generic direct-contact soil calculations.
Generic numerical standard (GNS): A pre-calculated chemical concentration that may be used when a property’s land use and exposure conditions match the assumptions behind the value.
Hazard index: A measure of potential non-cancer health effects. An index of 1 is the general target for a single chemical under the VAP framework.
High-frequency child exposure: A commercial land-use scenario where children may be present often enough to require a more protective exposure assessment.
Identified area: A part of a property where a release has occurred or may have occurred and where chemicals of concern are assessed.
Indoor-air standard: A chemical concentration in indoor air designed to protect occupants from inhalation exposure, including exposure caused by vapour intrusion.
Institutional control: A legal or administrative restriction used to limit land use, groundwater use or other activities so that exposure assumptions remain valid.
Point of compliance: The location at which environmental results are compared with the applicable standard.
Property-specific risk assessment: An assessment conducted under Rule 3745-300-09 using site-specific conditions instead of, or alongside, generic standards.
Receptor: A person, population or ecological organism that could be exposed to contamination.
Soil saturation concentration: The estimated concentration above which a chemical may occur as a separate phase or exceed the soil’s capacity to retain it. It can limit the final soil standard for some chemicals.
Supplemental criterion: A value that may support a property-specific risk assessment but is not necessarily an enforceable generic numerical standard.
Unrestricted potable-use standard: A groundwater concentration developed on the assumption that the water may be used for drinking, cooking, showering and bathing.
Vapour intrusion: The movement of volatile chemicals from contaminated soil or groundwater into an overlying building.
Volunteer: The person or organisation undertaking a cleanup under Ohio’s Voluntary Action Program.
This summary is intended as a practical overview. The official Ohio Administrative Code and the standards applicable to the specific property, chemical, medium and exposure scenario should be checked before making compliance or remediation decisions.
Related Articles to Ohio EPA updates
Insights and Hidden Impacts: US Environmental Standards and Guidelines
What are US environmental standards?
What are environmental guidelines and standards?
Video: The environmental standards workflow
