CAS 1310-58-3 · TSCA · United States of America

Potassium hydroxide (caustic potash) under TSCA

KOH · 氢氧化钾

Status: Listed. Potassium hydroxide is on the TSCA Inventory as a grandfathered pre-1979 substance and is currently listed as TSCA Active. No PMN is required. Same hazard profile as caustic soda (Skin Corr. 1A) drives parallel OSHA HazCom training + NFPA storage requirements. NOT on EPA RMP threshold list. NOT on DEA List I or List II. NOT on California Proposition 65 list. NOT on TRI Section 313 list (KOH delisted). NO active US AD/CVD case on Chinese-origin KOH (lighter trade-policy posture than caustic soda batch 1 lane). Section 301 List 3 25% additional duty applies on Chinese-origin KOH (HS 281520 / 281530). Major US domestic producers: Olin Corporation (Niagara Falls New York + Charleston Tennessee + Henderson Nevada + Augusta Georgia), Occidental Chemical (Wichita Kansas + Convent Louisiana), Westlake Corporation (Geismar Louisiana). US is comparatively self-sufficient in KOH but imports flow during plant outages.

The US KOH lane is dominated by **Section 301 List 3 25% additional duty** (lighter trade-policy stack than caprolactam batch 14 + AS batch 12 lanes). NO active US AD/CVD case on Chinese-origin KOH. TRI Form R reporting NOT required (KOH delisted). US is comparatively self-sufficient through Olin Corporation (4 sites), Occidental Chemical (2 sites), Westlake Corporation domestic supply. **Electronics-grade KOH for PV-cell etching** is the grade-specific application that imports satisfy; semiconductor and electronics-grade premium ~3-5x industrial-grade pricing. Biodiesel transesterification chain (KOH catalyst + methanol batch 3) drives ~25% of US KOH consumption. Major Chinese producers: Sinopec Beijing, Wansheng Chemical Anhui, Hubei Sanonda, Qingdao Soda Industry Shandong, Hubei Yihua. KOH is the **K-analogue of caustic soda** at ~30:1 smaller market scale: same hazard profile (Skin Corr. 1A drives parallel OSHA HazCom + NFPA storage compliance) but distinct end-use mix (biodiesel + soft-soap + K2CO3 + alkaline-battery electrolyte + agriculture).

Listing and threshold

Substance Potassium hydroxide (caustic potash) (CAS 1310-58-3), KOH
Regime US Toxic Substances Control Act (TSCA), administered by EPA
Jurisdiction United States of America
Status Listed
Tonnage threshold CDR (Chemical Data Reporting) threshold: 25,000 lb (11,340 kg) manufactured or imported per site per year

Classifications under this regime

  • OSHA Hazard Communication Standard (HCS): GHS H290 / H302 / H314
  • OSHA PEL: 2 mg/m³ ceiling (29 CFR 1910.1000 Table Z-1; verify against https://www.osha.gov/annotated-pels/table-z-1)
  • NIOSH REL: 2 mg/m³ ceiling
  • NOT on TSCA Section 4 test rule
  • NOT currently subject to TSCA Section 6 unreasonable-risk evaluation
  • NOT on TSCA Section 5(a)(2) Significant New Use Rule list
  • NOT on EPA RMP threshold list
  • NOT on DEA List I or List II
  • NOT on California Proposition 65 list (verify against OEHHA https://oehha.ca.gov/proposition-65/proposition-65-list before relying on negative listing)
  • NOT on TRI Section 313 list (KOH delisted)
  • DOT hazardous materials regulation (49 CFR 172.101): UN 1813 (solid) / UN 1814 (solution), Class 8, PG II
  • IARC: not classified
  • FDA 21 CFR 184.1631 GRAS (Generally Recognised As Safe) for food use as pH-adjustment agent

Restrictions and conditions of use

  • No TSCA-specific use restrictions for potassium hydroxide
  • OSHA-compliant SDS and workplace HazCom training required
  • NO active US AD/CVD case on Chinese-origin potassium hydroxide
  • Section 301 List 3 25% additional duty applies on Chinese-origin KOH (HS 281520 / 281530)
  • NFPA 30 storage requirements apply for solution lots; ATEX-zoned warehousing for solid lots
  • FDA 21 CFR 184.1631 approves KOH as food pH-adjustment agent
  • EPA Pesticide Registration: certain KOH-containing wood-preservative formulations subject to FIFRA registration

Importer obligations

TSCA is a self-certification regime: importers attest at customs entry that the substance is on the TSCA Inventory. The TSCA Section 13 Import Certification statement is filed via the customs broker on the entry summary (CBP Form 7501). The dominant practitioner-facing layer for KOH is **Section 301 List 3 25% additional duty** + OSHA HazCom training + NFPA storage compliance. NO active AD/CVD case so no AD margin documentation required (lighter than caprolactam batch 14 + AS batch 12 lanes). US is comparatively self-sufficient through Olin Corporation + Occidental Chemical + Westlake Corporation domestic supply; imports flow during plant outages and grade-specific applications (electronics-grade KOH for PV-cell etching).

Required documents

  • TSCA Section 13 Import Certification statement on customs entry
  • OSHA-compliant SDS (Safety Data Sheet) in 16-section GHS format reflecting H290 / H302 / H314 classification
  • Customs entry CBP Form 7501 with HS code 281520 (solid) or 281530 (solution) and Section 301 List 3 25% duty applied
  • CDR filing every 4 years if site exceeds 25,000 lb/yr threshold (next cycle 2026)
  • NFPA 30-compliant storage tank engineering documentation for bulk receipt
  • FDA 21 CFR 184.1631 conformity declaration for food-grade lots

Common compliance traps

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

  • **Section 301 List 3 25% additional duty** is the dominant tariff-stack layer (no AD on top); structurally lighter than caprolactam batch 14 + AS batch 12 lanes
  • OSHA PEL 2 mg/m³ ceiling is identical to NaOH (caustic soda batch 1)
  • TRI Form R reporting NOT required (KOH delisted from TRI)
  • US is comparatively self-sufficient in KOH through Olin Corporation (4 sites: Niagara Falls New York, Charleston Tennessee, Henderson Nevada, Augusta Georgia), Occidental Chemical (2 sites: Wichita Kansas, Convent Louisiana), Westlake Corporation (Geismar Louisiana); imports flow during plant outages and grade-specific applications
  • Electronics-grade KOH for PV-cell etching is grade-specific application that imports satisfy; semiconductor / electronics-grade premium ~3-5x industrial-grade pricing
  • Biodiesel transesterification (KOH catalyst + methanol batch 3) chain demand drives ~25% of US KOH consumption
  • Major Chinese producers: Sinopec Beijing, Wansheng Chemical Anhui, Hubei Sanonda, Qingdao Soda Industry Shandong, Hubei Yihua

Where to read next

For substance-level identifiers (formula, molecular weight, SMILES, InChIKey), GHS hazard profile, IMDG transport class, and full sourcing reference for potassium hydroxide (caustic potash), see the CAS 1310-58-3 sourcing reference.

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

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

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Read next

Cross-jurisdiction profile and sourcing references

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