Korean: 메칠이소치아졸리논 · CAS 2682-20-4 · Functions: preservative
Restricted MFDS restricted ingredients
Conditions (official MFDS text, Korean):
* 배합한도 : ∙ 사용 후 씻어내는 제품 0.0015% (단, 메칠클로로이소치아졸리논과 메칠이소치아졸리논 혼합물과 병행 사용 금지)
∙ 기타 제품에는 사용금지
Source: MFDS — cosmetic ingredient use restrictions · checked Oct 17, 2026
Approved preservative Annex V/39
Maximum: 0.0015% (of a mixture in the ratio 3:1 of 5-Chloro-2-methyl-isothiazol-3(2H)-one and 2-Methylisothiazol-3(2H)-one
Conditions: Product type: Rinse-off
Source: EU CosIng — Annex V · checked Oct 17, 2026
Approved preservative Annex V/57
Maximum: 0,0015 % Rinse-off products
Source: EU CosIng — Annex V · checked Oct 17, 2026
No specific rule on file. The FDA regulates few cosmetic ingredients by name; no rule does not mean approval.
How Methylisothiazolinone is treated in 7 more markets, from the overseas cosmetic regulation database compiled by Korea's MFDS. Always confirm with the regulator of that country before selling there.
| Market | Status | Conditions |
|---|---|---|
| CN China | Restricted | MFDS summary (Korean): <고시명 : 2-Methylisothiazol-3(2H)-one> * 【화장품 중 최대사용농도】 배합한도 (일반) : 0.01% <고시명 : Mixture of 5-chloro-2-methylisothiazol-3(2H)-one and 2-methylisothiazol-3(2H)-one with magnesium chloride and magnesium nitrate(of a mixture in the ratio 3:1 of 5-chloro-2-methylisothiazol 3(2H)-one and... |
| AS ASEAN (10 countries) | Restricted | MFDS summary (Korean): (9) Methylisothiazolinone is also regulated in entry 57. The two entries are mutually exclusive: the use of the mixture of Methylchloroisothiazolinone (and) Methylisothiazolinone is incompatible with the use of Methylisothiazolinone alone in the same product. * 단서조항(주석) : (9)... |
| JP Japan | Restricted | MFDS summary (Korean): （注1）空欄は、配合してはならないことを示し、○印は、配合の上限がないことを示す。 * 【100g당 최대 배합량 (점막에 사용하지 않고 씻어내는 화장품 -Cosmetics not used for mucosa and to be washed away)】 : 0.01 g * 【100g당 최대 배합량 (점막에 사용하지 않고 씻어내지 않는 화장품 - Cosmetics not used for mucosa and not to be washed away)】 : 0.01 g * 【100g당 최대 배합량 (점막에 사용하는 화장품 -... |
| TW Taiwan | Restricted | MFDS summary (Korean): ※ 未列於本表中之防腐劑成分，倘歐、美、日三國家地區政府已公告准用且有其限量管制規定者，我國亦依其限用標準准予使用。 倘前述三國家地區政府管理有差異時，則採其中限量規定方式最安全者。 ※ 本表所稱之口腔製劑，包含非藥用牙膏、漱口水類及美白牙齒類等化粧品。 * 단서조항 : ※ 未列於本表中之防腐劑成分，倘歐、美、日三國家地區政府已公告准用且有其限量管制規定者，我國亦依其限用標準准予使用。 倘前述三國家地區政府管理有差異時，則採其中限量規定方式最安全者。 ※ 本表所稱之口腔製劑，包含非藥用牙膏、漱口水類及美白牙齒類等化粧品。 ※ 본 표에 열거되지 않은 방부제 성분은 유럽, 미국,... |
| CA Canada | Restricted | 【Restrictions】 Conditions of Use by product type : (a) Not permitted in leave-on products. (b) Rinse-off products Note: If MI is present in a formulation with Methylisothiazolinone / Methylchloroisothiazolinone (MI/MCI) in combination, the cumulative, total concentration of MI and MI/MCI may not exceed 0.0015%. 【Restrictions】 Maximum Concentration Permitted : b) 0.0015% |
| BR Brazil | Restricted | MFDS summary (Korean): <보존제 : Mixture of 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one with magnesium and magnesium nitrate (3: 1) chloride (METHYL CHLOROISOTIAZOLINONE Methylisothiazolinone +)> * Restrictions 【Maximum concentration permitted at final product】 : 0.0015% (a mixture in... |
| AR Argentina | Restricted | MFDS summary (Korean): <보존제 : Mixture of 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one with magnesium and magnesium nitrate (3: 1) chloride (METHYL CHLOROISOTIAZOLINONE Methylisothiazolinone +)> * Restrictions 【Maximum concentration permitted at final product】 : 0.0015% (a mixture in... |
Source: MFDS cosmetic ingredient use restrictions — overseas regulations · checked Oct 17, 2026
METHYLISOTHIAZOLINONE 메칠이소치아졸리논
Information only, not medical advice. Rules change — always check the linked official source. If you are pregnant, have a skin condition or allergies, ask a dermatologist or pharmacist.
In the EU's CosIng records it is listed as “Approved preservative” (EU CosIng — Annex V). The maximum allowed is 0.0015% (of a mixture in the ratio 3:1 of…. It is allowed for that use within the stated conditions.
In Korea's MFDS records it is listed as “Restricted” (MFDS — cosmetic ingredient use restrictions). A restricted ingredient is allowed within the stated conditions.
We found no specific rule for it in the FDA's records. That is not an approval or a safety statement.
The EU's CosIng inventory lists its functions as: preservative.
Korea's MFDS standard Korean name is 메칠이소치아졸리논.
1 products we checked list it, for example Nature Republic Super Aqua Max Fresh Watery Cream.
CAS 2682-20-4 (from official records).