CAS 1305-62-0 · TSCA · United States of America

Calcium hydroxide (hydrated lime) under TSCA

Ca(OH)2 · 氢氧化钙

Status: Listed. Calcium hydroxide is on the TSCA Inventory and currently listed as TSCA Active. **OSHA PEL 5 mg/m3 8-hr TWA respirable, 15 mg/m3 total** at 29 CFR 1910.1000 Table Z-1 (verify against https://www.osha.gov/annotated-pels). NOT on EPA RMP threshold list. NOT on DEA scheduling. NOT on California Proposition 65 (verify against OEHHA https://oehha.ca.gov/proposition-65/proposition-65-list before relying on negative listing). NO active US AD/CVD case on Chinese-origin calcium hydroxide currently (verify against https://access.trade.gov/ before invoicing). Section 301 List 3 25% additional duty applies on Chinese-origin calcium hydroxide (HS 252220) (verify against current USTR Section 301 schedule before invoicing). Major US domestic producers (verify each company-site pair against the producer's public website before relying): Lhoist North America multi-site, Mississippi Lime Company multi-site, Carmeuse Americas multi-site, Graymont multi-site.

US calcium hydroxide lane: **OSHA PEL 5 mg/m3 respirable + Section 301 List 3 + NSF Standard 60 for water-treatment grade**. NOT on Cal Prop 65. NO active US AD/CVD case. Major US producers: Lhoist, Mississippi Lime, Carmeuse, Graymont.

Listing and threshold

Substance Calcium hydroxide (hydrated lime) (CAS 1305-62-0), Ca(OH)2
Regime US Toxic Substances Control Act (TSCA), administered by EPA
Jurisdiction United States of America
Status Listed
Tonnage threshold CDR threshold: 25,000 lb manufactured or imported per site per year

Classifications under this regime

  • OSHA HCS: GHS H315 / H318 / H335
  • OSHA PEL 29 CFR 1910.1000 Table Z-1: 5 mg/m3 8-hr TWA respirable, 15 mg/m3 total (verify against https://www.osha.gov/annotated-pels)
  • NIOSH REL: 5 mg/m3 8-hr TWA (verify against https://www.cdc.gov/niosh/npg/)
  • NOT subject to TSCA Section 6 Risk Evaluation
  • NOT on EPA RMP threshold list
  • NOT on DEA List I or List II
  • NOT on California Proposition 65 list (verify against OEHHA before relying on negative listing)
  • DOT 49 CFR 172.101: NOT regulated for industrial-grade Ca(OH)2 powder
  • IARC: not evaluated for calcium hydroxide as a discrete agent (verify against https://monographs.iarc.who.int/list-of-classifications)

Restrictions and conditions of use

  • OSHA-compliant SDS and workplace HazCom training required
  • NO active US AD/CVD case on Chinese-origin calcium hydroxide currently
  • Section 301 List 3 25% additional duty applies on Chinese-origin calcium hydroxide (HS 252220)
  • Safe Drinking Water Act / NSF Standard 60 certification typically required for water-treatment grade

Importer obligations

TSCA self-certification regime. Major US producers: Lhoist North America multi-site, Mississippi Lime Company multi-site, Carmeuse Americas multi-site, Graymont multi-site.

Required documents

  • TSCA Section 13 Import Certification on customs entry
  • OSHA SDS reflecting H315 / H318 / H335
  • CBP Form 7501 with HS 252220 + Section 301 List 3 25% duty
  • CDR filing every 4 years
  • NSF Standard 60 certification for water-treatment grade where applicable

Common compliance traps

The pitfalls that have bitten importers on this lane in the past. None of these is theoretical.

  • OSHA PEL 5 mg/m3 8-hr TWA respirable, 15 mg/m3 total
  • NO active US AD/CVD case
  • Section 301 List 3 25% additional duty applies
  • Safe Drinking Water Act / NSF Standard 60 certification typically required for water-treatment grade
  • Major US producers: Lhoist North America multi-site, Mississippi Lime Company, Carmeuse Americas, Graymont

Where to read next

For substance-level identifiers (formula, molecular weight, SMILES, InChIKey), GHS hazard profile, IMDG transport class, and full sourcing reference for calcium hydroxide (hydrated lime), see the CAS 1305-62-0 sourcing reference.

For grade-by-grade buying notes, freight maths, supplier-tier pricing, and a worked landed-cost example, the calcium hydroxide (hydrated lime) cornerstone hub covers the full sourcing chain.

For the structure and history of TSCA, see the TSCA glossary entry.

Need cross-jurisdiction compliance support on this substance? Run it through the REACH / TSCA / IECSC / AICIS / K-REACH checker, or send us the substance and the destination and we will quote FOB China and CIF / DDP landed including the regulatory work on the destination side.

Read next

Cross-jurisdiction profile and sourcing references

Referenced in

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