Chromium(III) / Trivalent Chromium in the yard and garden
Low risk for your yardChromium(III) is an essential trace element required for glucose metabolism and is non-carcinogenic at dietary exposure levels. Toxicity risk is minimal in general population exposure; occupational dust inhalation may pose moderate acute respiratory irritation but does not establish carcinogenic risk. Systemic absorption is limited.
What is chromium(iii) / trivalent chromium?
The IUPAC name is chromium.
Also known as: chromium, Chrome, Chromium metal, Chrom.
- IUPAC name
- chromium
- CAS number
- 7440-47-3
- Molecular formula
- Cr
- Molecular weight
- 51.996 g/mol
- SMILES
- [Cr]
- PubChem CID
- 23976
Risk for people, pets,
Low riskChromium(III) is an essential trace element required for glucose metabolism and is non-carcinogenic at dietary exposure levels. Toxicity risk is minimal in general population exposure; occupational dust inhalation may pose moderate acute respiratory irritation but does not establish carcinogenic risk. Systemic absorption is limited.
Regulatory consensus
7 regulatory and scientific bodies have classified Chromium(III) / Trivalent Chromium. The classifications differ — that's the data.
| Agency | Year | Classification | Notes |
|---|---|---|---|
| IARC | 1990 | Group 3 (Not classifiable as to carcinogenicity in humans) | Insufficient evidence of carcinogenicity in humans and animals to establish carcinogenic classification. Inhalation of Cr(III) dust in occupational settings does not demonstrate convincing carcinogenic risk compared to Cr(VI) |
| US EPA | 2024 | Not designated as carcinogen | Chromium(III) is not listed in EPA's reference dose or reference concentration assessments for carcinogenicity. Generally recognized as safe (GRAS) at trace dietary levels; OSHA PEL for inhalation 5 mg/m³ |
| NTP | 2024 | Not listed | Chromium(III) compounds are not included in the National Toxicology Program Report on Carcinogens due to lack of sufficient evidence of carcinogenic potential |
| EPA CTX / IARC | — | Group 3 - Not classifiable as to its carcinogenicity to humans | |
| EPA CTX / Health Canada | — | Group I: CEPA (carcinogenic to humans) | |
| EPA CTX / Genetox | — | Genotoxicity: negative (Ames: negative, 1 positive / 5 negative reports) | |
| EPA CTX / Genetox | — | Genotoxicity: negative (Ames: negative, 1 positive / 5 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) / trivalent chromium
- 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) / Trivalent Chromium:
-
Tocopherol (Vitamin E) based antioxidants
Trade-offs: Lower thermal stability than synthetic BHT/BHA for some polymer applications.Relative cost: 2-5× conventional
Frequently asked questions
Is chromium(iii) / trivalent chromium safe for your yard?
Chromium(III) is an essential trace element required for glucose metabolism and is non-carcinogenic at dietary exposure levels. Toxicity risk is minimal in general population exposure; occupational dust inhalation may pose moderate acute respiratory irritation but does not establish carcinogenic risk. Systemic absorption is limited.
What products contain chromium(iii) / trivalent chromium?
Chromium(III) / Trivalent Chromium 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) / trivalent chromium?
Chromium(III) / Trivalent Chromium has been classified by 7 agencies including IARC, US EPA, NTP, EPA CTX / IARC, EPA CTX / Health Canada, 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) / Trivalent Chromium in the outdoor app
Look up products containing chromium(iii) / trivalent chromium, compare to alternatives, and explore the full data record.
Open in outdoor View raw API dataSources (5)
- IARC Monographs on the Evaluation of Carcinogenic Risks to Humans — Chromium, Nickel and Welding (Volume 49) (1990) — regulatory
- US EPA Integrated Risk Information System (IRIS) — Chromium(III) (2024) — regulatory
- National Research Council — Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (2005) — regulatory
- OSHA Inorganic Chromium(III) Occupational Exposure Standard — 29 CFR 1910.1000 (1990) — regulatory
- Occupational Exposure to Chromium(III) Compounds — Respiratory and Systemic Effects in Tanning and Welding Industries (2018) — research
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 →