Chromium(III) sulfate (tanning agent) in the yard and garden
Moderate risk for your yardChromium(III) sulfate presents a low to moderate risk to human adults. IARC Group 3 for Cr(III) — not classifiable as carcinogen — distinguishes it clearly from carcinogenic Cr(VI). The direct carcinogenic risk from Cr(III) sulfate at typical tannery occupational and consumer leather exposures is not established. The primary consumer concern is Cr(VI) contact dermatitis from chrome-tanned leather articles: even compliant leather (Cr(VI) <3 mg/kg per EU regulation) can sensitize chrome-allergic individuals. Chrome allergy affects approximately 3–4% of patch-tested populations and is a major cause of occupational dermatitis in construction (cement) and tannery workers. Individuals already sensitized to Cr(VI) react to chrome-tanned leather shoes via perspiration-induced Cr(VI) release. Tannery workers are exposed to Cr(III) sulfate dust and mist at occupational levels requiring respiratory and dermal protection.
What is chromium(iii) sulfate (tanning agent)?
The IUPAC name is bis(chromium(3+));trisulfate.
Also known as: bis(chromium(3+));trisulfate, CHROMIC SULFATE, Chromium(III) sulfate, Chromic sulphate.
- IUPAC name
- bis(chromium(3+));trisulfate
- CAS number
- 10101-53-8
- Molecular formula
- Cr2O12S3
- Molecular weight
- 392.2 g/mol
- SMILES
- [O-]S(=O)(=O)[O-].[O-]S(=O)(=O)[O-].[O-]S(=O)(=O)[O-].[Cr+3].[Cr+3]
- PubChem CID
- 24930
Risk for people, pets,
Moderate riskChromium(III) sulfate presents a low to moderate risk to human adults. IARC Group 3 for Cr(III) — not classifiable as carcinogen — distinguishes it clearly from carcinogenic Cr(VI). The direct carcinogenic risk from Cr(III) sulfate at typical tannery occupational and consumer leather exposures is not established. The primary consumer concern is Cr(VI) contact dermatitis from chrome-tanned leather articles: even compliant leather (Cr(VI) <3 mg/kg per EU regulation) can sensitize chrome-allergic individuals. Chrome allergy affects approximately 3–4% of patch-tested populations and is a major cause of occupational dermatitis in construction (cement) and tannery workers. Individuals already sensitized to Cr(VI) react to chrome-tanned leather shoes via perspiration-induced Cr(VI) release. Tannery workers are exposed to Cr(III) sulfate dust and mist at occupational levels requiring respiratory and dermal protection.
Regulatory consensus
3 regulatory and scientific bodies have classified Chromium(III) sulfate (tanning agent). The classifications differ — that's the data.
| Agency | Year | Classification | Notes |
|---|---|---|---|
| IARC | 2012 | Group 3 — not classifiable as to its carcinogenicity to humans (chromium(III) compounds — IARC Monographs Volume 49, 1990; Volume 100C, 2012; inadequate animal and human evidence for Cr(III); distinct from chromium(VI) compounds which are IARC Group 1; primary concern is Cr(III) to Cr(VI) oxidation in chrome-tanned leather causing contact dermatitis) | |
| EPA CTX / Genetox | — | Genotoxicity: negative (Ames: None, 0 positive / 2 negative reports) | |
| EPA CTX / Genetox | — | Genotoxicity: negative (Ames: None, 0 positive / 2 negative reports) |
Regulators apply different standards of evidence — animal-data weighting, exposure-pattern assumptions, epidemiological power thresholds — which is why two scientific bodies can review the same data and reach different conclusions. The disagreement is the data.
Where your yard encounter chromium(iii) sulfate (tanning agent)
- Contaminated Water — Mining site runoff, Industrial discharge areas, Drinking water from old infrastructure
- Soil Contamination — Industrial sites, Smelter areas, Battery recycling facilities
- Food Chain — Fish from contaminated waters, Shellfish from polluted areas, Crops grown in contaminated soil
Safer alternatives
Lower-risk approaches that achieve a similar outcome to Chromium(III) sulfate (tanning agent):
-
Safer process chemistry; Green chemistry alternatives; Exposure controls
Trade-offs: Requires R&D investment to redesign synthesis routes; may reduce yield or throughput initially; long-term benefits include reduced waste treatment costs, regulatory compliance, and worker safety; 12 Principles of Green Chemistry framework available.Relative cost: 2-5×
Frequently asked questions
Is chromium(iii) sulfate (tanning agent) safe for your yard?
Chromium(III) sulfate presents a low to moderate risk to human adults. IARC Group 3 for Cr(III) — not classifiable as carcinogen — distinguishes it clearly from carcinogenic Cr(VI). The direct carcinogenic risk from Cr(III) sulfate at typical tannery occupational and consumer leather exposures is not established. The primary consumer concern is Cr(VI) contact dermatitis from chrome-tanned leather articles: even compliant leather (Cr(VI) <3 mg/kg per EU regulation) can sensitize chrome-allergic individuals. Chrome allergy affects approximately 3–4% of patch-tested populations and is a major cause of occupational dermatitis in construction (cement) and tannery workers. Individuals already sensitized to Cr(VI) react to chrome-tanned leather shoes via perspiration-induced Cr(VI) release. Tannery workers are exposed to Cr(III) sulfate dust and mist at occupational levels requiring respiratory and dermal protection.
What products contain chromium(iii) sulfate (tanning agent)?
Chromium(III) sulfate (tanning agent) appears in: Mining site runoff (Contaminated water); Industrial discharge areas (Contaminated water); Industrial sites (Soil contamination); Smelter areas (Soil contamination); Fish from contaminated waters (Food chain).
Why do regulators disagree about chromium(iii) sulfate (tanning agent)?
Chromium(III) sulfate (tanning agent) has been classified by 3 agencies including IARC, EPA CTX / Genetox, EPA CTX / Genetox, with differing conclusions. Regulators apply different standards of evidence (animal data weighting, exposure-pattern assumptions, epidemiological power thresholds), which is why two scientific bodies can review the same data and reach different conclusions. See the regulatory consensus table on this page for the full picture.
See Chromium(III) sulfate (tanning agent) in the outdoor app
Look up products containing chromium(iii) sulfate (tanning agent), compare to alternatives, and explore the full data record.
Open in outdoor View raw API dataSources (1)
- IARC Monographs Volume 49 1990 Volume 100C 2012 Chromium(III) Compounds Group 3; Cr(VI) IARC Group 1 Distinction; Chrome Tanning 80% Global Leather Production; EU Regulation 301/2014 Cr(VI) 3 mg/kg Leather Limit; Chrome Allergy Type IV Dermatitis 3-4% Prevalence; Cr(III)-to-Cr(VI) Oxidation UV Alkaline Microbial; Tannery Wastewater Chromium Pollution; UK WEL 0.5 mg/m3 Cr(III); EU CLP Aquatic Chronic 3 (2012) — regulatory
Reference data, not professional advice. Aggregates publicly available regulatory and scientific data; not a substitute for veterinary, medical, legal, or regulatory advice. Why we built ALETHEIA →