Overview

Ohio’s VAP establishes generic direct-contact soil standards for metals under OAC 3745-300-08. These standards represent the single-chemical GDCSS - the lowest applicable value across all direct-contact exposure pathways for each land use category.

The values below are from the current CIDARS database (February 2025 version, accompanying the VAP rules effective February 16, 2025).

Unlike VOCs, metals in soil generally don’t present a vapor intrusion concern (mercury is the notable exception). The driving pathways for metals are typically direct contact (ingestion and dermal absorption) and soil leaching to groundwater.

Generic Direct-Contact Soil Standards

Showing 54 of 54 chemicals

Chemical	CAS Number	Residential (mg/kg)	Commercial/Industrial (mg/kg)
Aluminum Phosphide	20859-73-8	63	1,900
Antimony (Metallic)	7440-36-0	63	1,900
Antimony Trioxide	1309-64-4	400,000	1,000,000
Arsenic, Inorganic	7440-38-2	14	100
Asbestos (fiber >10 micrometers)	1332-21-4	NL	NL
Barium	7440-39-3	30,000	760,000
Beryllium and Compounds	7440-41-7	310	8,800
Cadmium	7440-43-9	14	350
Chlorine	7782-50-5	0.4797	2.015
Chromium(III)	16065-83-1	79,000	470,000
Chromium(VI)	18540-29-9	5.9666	240
Chromium, Total	7440-47-3	NL	NL
Cobalt Compounds	7440-48-4	47	1,400
Copper	7440-50-8	6,300	190,000
Disodium Phosphate	7558-79-4	160,000	1,000,000
Hydrogen Chloride	7647-01-0	1,000,000	1,000,000
Hydrogen Fluoride	7664-39-3	6,300	190,000
Hydrogen Sulfide	7783-06-4	72,000	1,000,000
Fluorine (Soluble Fluoride)	7782-41-4	9,400	280,000
Manganese Compounds	7439-96-5	3,600	88,000
Mercury and Compounds	7439-97-6	3.1	3.1
Nickel Soluble Salts	7440-02-0	2,800	52,000
Phosphine	7803-51-2	47	1,400
Selenium	7782-49-2	780	23,000
Selenious Acid	7783-00-8	780	23,000
Silver	7440-22-4	780	23,000
Sodium Azide	26628-22-8	630	19,000
Sodium Fluoride	7681-49-4	7,800	230,000
Sodium Fluoroacetate	62-74-8	2.5	51
Sodium Tripolyphosphate	7758-29-4	160,000	1,000,000
Sulfuric Acid	7664-93-9	250,000	1,000,000
Thallium (Soluble Salts)	7440-28-0	NL	NL
Titanium Tetrachloride	7550-45-0	200,000	830,000
Trisodium Phosphate	7601-54-9	160,000	1,000,000
Vanadium Compounds	7440-62-2	780	23,000
Zinc and Compounds	7440-66-6	47,000	1,000,000
Zinc Phosphide	1314-84-7	47	1,400
Calcium Cyanide	592-01-8	160	4,700
Copper Cyanide	544-92-3	780	23,000
Cyanide (CN-)	57-12-5	51	400
Cyanogen	460-19-5	160	4,700
Cyanogen Bromide	506-68-3	14,000	420,000
Cyanogen Chloride	506-77-4	7,800	230,000
Hydrogen Cyanide	74-90-8	51	400
Potassium Cyanide	151-50-8	310	9,300
Potassium Silver Cyanide	506-61-6	780	23,000
Silver Cyanide	506-64-9	16,000	470,000
Sodium Cyanide	143-33-9	160	4,700
Zinc Cyanide	557-21-1	7,800	230,000
Lead Acetate	301-04-2	52	340
Lead and Compounds*	7439-92-1	200	800
Lead Phosphate	7446-27-7	1,600	15,000
Lead Subacetate	1335-32-6	290	1,900
Tetraethyl Lead	78-00-2	0.0156	0.467

Qualifier key:

* = See paragraph (C)(3)(e) of rule 3745-300-08 of the Administrative Code - lead is excluded from the cumulative risk calculation.

Practical Notes for Consultants

Lead - The 200 mg/kg Standard

Lead is the metal that generates the most discussion at Ohio cleanup sites. The VAP sets the residential GDCSS at 200 mg/kg by rule (not from the standard risk equations). This now matches EPA’s updated RSL of 200 mg/kg, which was lowered from 400 mg/kg based on more recent blood-lead modeling.

For commercial/industrial sites, the VAP sets the C/I GDCSS at 800 mg/kg, but the construction worker standard is far lower at 200 mg/kg - the same value as the residential standard. This means a commercial property with lead at 500 mg/kg would meet the C/I standard but fail the construction worker standard - a nuance that matters during demolition and redevelopment, when workers disturb soil that is otherwise acceptable for ongoing commercial use.

In urban Ohio, background lead concentrations frequently exceed 200 mg/kg, especially near roads with historic leaded gasoline deposition and near older buildings with lead paint. Background characterization may be necessary to demonstrate that concentrations above 200 mg/kg represent ambient conditions rather than a release.

Arsenic - Background vs. Contamination

Ohio soils naturally contain arsenic, typically in the range of 5-20 mg/kg depending on geology. The residential GDCSS of 14 mg/kg falls right in the middle of that range, which means you’ll frequently encounter sites where arsenic exceeds the standard due to natural background, not contamination.

If you suspect background is driving your arsenic results, you’ll need to collect background samples from areas unaffected by site activities and perform a statistical comparison. Ohio EPA’s Technical Guidance Manual provides guidance on background sample collection and statistical methods.

Hexavalent Chromium - Know When to Speciate

The gap between Cr(III) at 79,000 mg/kg and Cr(VI) at 6 mg/kg residential is enormous - over four orders of magnitude. If your site has any history of chrome plating, leather tanning, wood treatment (CCA), or industrial metal finishing, spend the money on speciation analysis (EPA Method 7199 or 7196A for soil). A total chromium result of 50 mg/kg that’s entirely Cr(III) is a non-issue. The same result at 10% Cr(VI) means you have 5 mg/kg hex chrome - close to the 6 mg/kg residential standard.

Mercury - The Exception Among Metals

Mercury is the only common metal with a significant vapor pathway. The residential GDCSS of 3.1 mg/kg is driven by soil saturation, and it’s the same across residential, C/I, and construction worker scenarios. Mercury also has indoor air vapor intrusion standards in CIDARS, unlike other metals. If you encounter mercury contamination in soil, you need to evaluate the vapor pathway in addition to direct contact and leaching.

XRF Field Screening for Metals

Handheld X-ray fluorescence (XRF) analyzers are a powerful tool for real-time metals screening in soil. They can measure most metals of concern (arsenic, lead, chromium, cadmium, zinc, copper, etc.) directly in the field in 30-60 seconds per reading with reasonable accuracy at concentrations relevant to VAP standards.

XRF results are not a substitute for laboratory analysis for compliance purposes, but they allow you to make better decisions about where to collect confirmation samples, how to delineate contamination, and when to stop excavating during removal actions. For lead site work especially, XRF can save thousands of dollars in lab costs by directing your sampling program in real time.