What is the tonnage threshold for K-REACH on magnesium oxide (magnesia)?

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)

CAS 1309-48-4 · K-REACH · Republic of Korea

Magnesium oxide (magnesia) under K-REACH

MgO · 氧化镁

Status: Registered. Magnesium oxide is registered under K-REACH. NOT on Korea TCCA Toxic Chemicals list (verify against the current TCCA Toxic Chemicals list at https://www.nics.go.kr/ before relying). NOT on Korean Drug Management Act precursor list. NO active Korean AD/CVD case on Chinese-origin magnesium oxide currently (verify against https://www.kita.org/ or Korea Trade Commission filings before invoicing). **Korean Food Code recognises magnesium oxide as a food additive** (verify against MFDS / Korean Food Code before relying). Korea has limited domestic magnesite reserves; structurally net-importer for refractory plus industrial plus pharma grades, with significant import dependency on Chinese magnesia for steel + cement + glass refractory linings. KCFTA preferential zero-duty applies for Chinese-origin imports.

K-REACH treats magnesium oxide as a routine registered substance with no TCCA overlay. Korea limited domestic magnesite reserves; structurally net-importer with significant Chinese-magnesia dependency for refractory chain. NO active Korean AD/CVD case. **Magnesium oxide distinguishing pattern across all 5 regimes**: Three commercial grades (CCM caustic-calcined ~700-1000 C, DBM dead-burned ~1700-2000 C, FM fused ~2800 C electric arc) from magnesite (MgCO3) calcination or seawater / brine extraction + completes alkaline-earth oxide chain alongside CaO batch 67 + refractory (steel + cement + glass) plus animal feed plus pharma antacid / laxative plus food-grade E530 plus magnesium metal feedstock downstream chains + low hazard profile across regimes (respirable dust + fume metal-fume-fever potential) + Magnesia Carbon Bricks AD/CVD orders A-570-954 / C-570-955 in US + Chinese export-licensing controls.

Listing and threshold

Substance	Magnesium oxide (magnesia) (CAS 1309-48-4), MgO
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: NOT typically classified as hazardous beyond particulate dust / fume
NOT on Korea TCCA Toxic Chemicals list
NOT on Korean Drug Management Act precursor list
Korean Customs Service (KCS) HS code: 251990
**Korean Food Code food additive** (verify against MFDS / Korean Food Code before relying)
IARC: Not classified

Restrictions and conditions of use

No TCCA Toxic Chemicals Handling Permit required
KOSHA MSDS in Korean required at workplace (low hazard, respirable dust / fume applies)
NO active Korean AD/CVD case on Chinese magnesium oxide currently
KCFTA preferential zero-duty applies (HS 251990)
Korean Food Code compliance for food-grade use

Importer obligations

Korean importer of record must hold K-REACH registration. Korea has limited domestic magnesite reserves; structurally net-importer with significant import dependency on Chinese magnesia for steel + cement + glass refractory linings.

Required documents

K-REACH registration number on Korean side
Korean MSDS (with respirable particulate dust / fume handling notes)
KCS declaration with HS 251990
China-Korea FTA Form CO
Korean Food Code certification for food-grade use

Common compliance traps

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

Korea has limited domestic magnesite reserves; structurally net-importer with significant Chinese-magnesia import dependency for refractory chain
KCFTA preferential zero-duty applies
NO active Korean AD/CVD case
NOT on TCCA Toxic Chemicals list
Korean Food Code food-additive compliance for food-grade use

Where to read next

For substance-level identifiers (formula, molecular weight, SMILES, InChIKey), GHS hazard profile, IMDG transport class, and full sourcing reference for magnesium oxide (magnesia), see the CAS 1309-48-4 sourcing reference.

For grade-by-grade buying notes, freight maths, supplier-tier pricing, and a worked landed-cost example, the magnesium oxide (magnesia) 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.

Cross-jurisdiction profile and sourcing references

Referenced in

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