CAS 101-68-8 · K-REACH · Republic of Korea

4,4'-MDI (4,4'-methylenediphenyl diisocyanate) under K-REACH

C15H10N2O2 · 4,4-亚甲基二苯基二异氰酸酯

Status: Registered. 4,4'-MDI is registered under K-REACH and listed as a Priority Existing Chemical (PEC). Korean GHS classification matches REACH (Resp. Sens. 1 + Carc 2 + Skin Sens. 1 + Acute Tox. 4 inhalation + STOT SE 3 + STOT RE 2). NOT on Korea TCCA Toxic Chemicals list (lighter than aniline batch 26 + benzene batch 22 + EO batch 28 + PO batch 29). NOT on Korean Drug Management Act precursor list. NO active Korean AD/CVD case on Chinese-origin 4,4'-MDI. **Korea has substantial domestic 4,4'-MDI production**: Hyosung Chemicals (Yongjeong + Yeosu), Kumho Mitsui Chemicals (Yeosu integrated TDI + MDI chain); structurally balanced. KCFTA preferential zero-duty applies for Chinese-origin imports.

K-REACH treats 4,4'-MDI as a routine PEC-registered substance with no TCCA overlay (lighter than aniline batch 26 + benzene batch 22 + EO batch 28 + PO batch 29). Korea has **substantial domestic 4,4'-MDI production at Yeosu** (Hyosung Chemicals + Kumho Mitsui Chemicals) integrated with aniline + TDI chain; structurally balanced. NO active Korean AD/CVD case. KCFTA preferential zero-duty supports Chinese-origin supplemental supply. Korean downstream consumers: Hyundai Motor + KIA (automotive PU foam + elastomer), Samsung SDI (battery-grade PU adhesives), Korean refrigerator + appliance sector (rigid PU foam insulation), Korean construction sector. **4,4'-MDI distinguishing pattern across all 5 regimes**: closes aniline batch 26 chain (downstream MDI product) + Resp. Sens. 1 (H334) most-restricted respiratory sensitiser in dataset + Annex XVII Restriction 56 EU-wide diisocyanate training requirement effective 24 February 2022 + Wanhua Chemical Yantai world's largest MDI producer ~3.6 Mt/yr MDI + polyurethane chain primary downstream (rigid + flexible PU foam, CASE elastomers, ~85% combined).

Listing and threshold

Substance 4,4'-MDI (4,4'-methylenediphenyl diisocyanate) (CAS 101-68-8), C15H10N2O2
Regime Korea Act on the Registration and Evaluation of Chemicals (Act No. 11789, "K-REACH" amended 2018)
Jurisdiction Republic of Korea
Status Registered
Tonnage threshold K-REACH registration required for existing chemicals manufactured or imported >1 tonne/year (verified per Korean Ministry of Environment / NIER guidance, https://chemical.chemlinked.com/chempedia/k-reach; threshold for new substances was reduced from 0.1 t/y to 1 t/y effective 1 January 2025 per K-REACH 2025 amendment)

Classifications under this regime

  • Korean GHS classification: Carc. 2 (H351), Acute Tox. 4 inhalation (H332), Skin Irrit. 2 (H315), Eye Irrit. 2 (H319), Resp. Sens. 1 (H334), Skin Sens. 1 (H317), STOT SE 3 (H335), STOT RE 2 (H373)
  • Signal word: DANGER. GHS pictograms: GHS07 + GHS08
  • Korea Occupational Safety and Health Act (KOSHA) workplace exposure standard: 0.005 ppm 8-hr TWA (tight due to Resp. Sens. 1)
  • NOT on Korea TCCA Toxic Chemicals list
  • NOT on Korean Drug Management Act precursor list
  • Korean Customs Service (KCS) HS code: 292910
  • IARC: nitric acid itself is not separately classified; occupational exposure to strong-inorganic-acid mists containing sulfuric acid was classified IARC Group 1 (laryngeal cancer) in Monograph Volume 54 (1992) (verify the current classification and Monograph volume against https://monographs.iarc.who.int/list-of-classifications before relying on the inorganic-acid-mist read-across for nitric acid)

Restrictions and conditions of use

  • No TCCA Toxic Chemicals Handling Permit required
  • No Chemical Accident Prevention Plan (CAPP) required
  • No Korean Drug Management Act precursor obligations
  • Korea Industrial Safety and Health Act (KOSHA) MSDS in Korean required at workplace
  • Korea Customs Service requires K-REACH registration number on import declaration
  • NO active Korean AD/CVD case on Chinese-origin 4,4'-MDI currently
  • KCFTA preferential zero-duty applies to Chinese-origin 4,4'-MDI (HS 292910)
  • **Workplace exposure-control + occupational asthma surveillance + medical surveillance** required for Resp. Sens. 1 substances

Importer obligations

The Korean importer of record must hold K-REACH registration. For 4,4'-MDI this is a routine PEC registration with no TCCA overlay. Korea has substantial domestic 4,4'-MDI production at Yeosu (Hyosung Chemicals + Kumho Mitsui Chemicals) integrated with aniline + TDI chain; supplemental imports flow during plant outages. Korean downstream consumers: Hyundai Motor + KIA (automotive PU foam + elastomer), Samsung SDI (battery-grade PU adhesives), Korean refrigerator + appliance sector (rigid PU foam insulation), Korean construction sector (insulation + sealants).

Required documents

  • K-REACH registration number on Korean side (registrant or OR-appointed)
  • Korean-language MSDS compliant with Korean GHS reflecting H315 / H317 / H319 / H332 / H334 / H335 / H351 / H373 classification
  • Korean Customs Service (KCS) declaration with HS code 292910
  • China-Korea FTA Form CO certificate of origin for preferential treatment
  • Industrial-grade specification certificate (minimum 99% purity)

Common compliance traps

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

  • Korean GHS hazard-statement codes use H-codes mapped to Korean translations
  • NOT on TCCA Toxic Chemicals list (lighter than aniline batch 26 + benzene batch 22 + EO batch 28 + PO batch 29)
  • **Workplace exposure-control + occupational asthma surveillance + medical surveillance** required for Resp. Sens. 1 substances under Korean Industrial Safety and Health Act
  • Korea has substantial domestic 4,4'-MDI production at Yeosu (Hyosung Chemicals + Kumho Mitsui Chemicals) integrated with aniline + TDI chain
  • KCFTA preferential zero-duty applies; verify producer-specific eligibility
  • No active Korean AD/CVD case on Chinese 4,4'-MDI currently
  • Korean downstream consumers: Hyundai Motor + KIA (automotive PU foam + elastomer), Samsung SDI (battery-grade PU adhesives), Korean refrigerator + appliance sector (rigid PU foam insulation), Korean construction sector

Where to read next

For substance-level identifiers (formula, molecular weight, SMILES, InChIKey), GHS hazard profile, IMDG transport class, and full sourcing reference for 4,4'-mdi (4,4'-methylenediphenyl diisocyanate), see the CAS 101-68-8 sourcing reference.

For grade-by-grade buying notes, freight maths, supplier-tier pricing, and a worked landed-cost example, the 4,4'-mdi (4,4'-methylenediphenyl diisocyanate) cornerstone hub covers the full sourcing chain.

For the structure and history of K-REACH, see the K-REACH 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.

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