METHYLCHLOROISOTHIAZOLINONE

RestrictedCAS 26172-55-421 regulations across 20 markets

METHYLCHLOROISOTHIAZOLINONE is a cosmetic ingredient classified as Preservative. Also known as CAS 26172-55-4. It is regulated in 20 markets including UAE, Australia, Bahrain.

Also Known As

CAS Number
26172-55-4, 2682-20-4, 55965-84-9

Market Overview — 29 Markets

European Union1
United Kingdom2
United States
California
Maryland
Washington
Canada1
Brazil1
South Korea1
Japan1
Taiwan1
Australia1
Singapore1
Malaysia1
Thailand1
Indonesia1
Vietnam1
Philippines1
UAE1
Saudi Arabia1
Qatar1
Oman1
Kuwait1
Bahrain1
Russia
Belarus
Kazakhstan
Armenia
Kyrgyzstan

Detailed Regulations

Europe3 regulations
European UnionRestrictedAnnex V #39
Chemical name
Mixture of 5-Chloro-2-methyl-isothiazol-3(2H)-one and 2-Methylisothiazol-3(2H)-one with magnesium chloride and magnesium nitrate
CAS
26172-55-4, 2682-20-4, 55965-84-9
Max concentration
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
Product type
Rinse-off

Source: EC 1223/2009 Annex V

United KingdomRestrictedAnnex V #39
Chemical name
Mixture of 5-Chloro-2-methyl-isothiazol-3(2H)-one and 2-methylisothiazol-3(2H)-one
CAS
26172-55-4, 2682-20-4, 55965-84-9
Max concentration
0,0015 % (of a mixture in the ratio 3:1 of 5-chloro-2-methylisothiazol 3(2H)-one and 2-methylisothiazol-3 (2H)-one)
Product type
Rinse-off products
Conditions of use
Max: 0,0015 % (of a mixture in the ratio 3:1 of 5-chloro-2-methylisothiazol 3(2H)-one and 2-methylisothiazol-3 (2H)-one)

Source: UK retained EC 1223/2009 Annex V

United KingdomRestrictedAnnex V #57
Chemical name
2-Methyl-2H-isothiazol-3-one
CAS
2682-20-4
Max concentration
0,0015 %
Product type
Rinse-off products
Conditions of use
Max: 0,0015 %

Source: UK retained EC 1223/2009 Annex V

Americas2 regulations
CanadaRestrictedAnnex Table 2 (Restricted)
Chemical name
Methylisothiazolinone / Methylchloroisothiazolinone, in combination
CAS
26172-55-4
Max concentration
b) 0.0015%
Conditions of use
a) Not permitted in leave-on products. b) Rinse-off products Note: MCI is only permitted when present in combination with MI. If MI/MCI is present in a formulation with MI alone, the cumulative, total concentration of MI/MCI and MI may not exceed 0.0015%.

Source: Health Canada Cosmetic Ingredient Hotlist

BrazilRestrictedAnnex RDC_528 #35
Chemical name
Mistura de 5-cloro-2-metil-4-is otiazolina-3-ona e 2-metil-4-isotiazo lina-3-ona com cloreto de magnésio e nitrato de magnésio (3:1)
CAS
26172-55-4
Max concentration
0,0015% (de uma mistura em proporções 3:1 de 5-Chloro-2-methyl- isothiazol-3(2H)-on e e 2- Methylisothiazol-3 (2H)-one) em produtos que se enxáguem.
Conditions of use
Limitations: -Proibido em produtos que não se enxáguem (incluindo os lenços umedecidos ). -A utilização da mistura de methylchlor oisothiazoli none e methylisothi azolinone é incompatíve l com a utilização de methylisothi azolinone sozinha em um mesmo produto.

Source: ANVISA RDC 528

East Asia & Oceania4 regulations
South KoreaRestrictedAnnex restricted #M1325
Chemical name
Methylchloroisothiazolinone
Conditions of use
* 배합한도 : ∙ 사용 후 씻어내는 제품에 0.0015% (메칠클로로이소치아졸리논:메칠이소치아졸리논=(3:1)혼합물로서) ∙ 기타 제품에는 사용금지

Source: MFDS Korea Cosmetics Regulation

JapanRestrictedAnnex Appendix 3 (Preservatives) #3-2
Chemical name
Methylchloro isothiazolinone and methyl isothiazolinone solution
Max concentration
0.10%
Product type
Rinse-off (cosmetics washed away after use)
Conditions of use
Aqueous solution containing 1.0-1.3% 5-chloro-2-methyl-4-isothiazolin-3-one and 0.30-0.42% 2-methyl-4-isothiazolin-3-one

Source: MHLW Standards for Cosmetics (Notification No.331 of 2000)

TaiwanRestrictedAnnex Preservatives List #30
Chemical name
Mixture of 5-Chloro-2-methyl-isothiazol-3(2H)-one and 2-Methylisothiazol-3(2H)-one with magnesium chloride and magnesium nitrate
CAS
55965-84-9, 26172-55-4, 2682-20-4
Max concentration
0.0015 %
Product type
R i nse off products
Conditions of use
Mixture in the ratio 3:1 of 5-Chloro-2-methyl-isothia zol-3(2H)-one and 2- Methylisothiazol-3(2H)-one

Source: TFDA Cosmetics Regulations

AustraliaRestrictedAnnex Schedule 6 (Poison) #SUSMP Schedule 6
Chemical name
METHYLCHLOROISOTHIAZOLINONE except
Conditions of use
(a) in rinse-off cosmetic preparations or therapeutic goods intended for topical rinse-off application containing 0.0015% or less of methylchloroisothiazolinone and methylisothiazolinone in total; or (b) in other preparations that are not intended for direct application to the skin containing 0.1% or less of methylchloroisothiazolinone and methylisothiazolinone in total.

Source: TGA SUSMP F2026L00060

ASEAN6 regulations
SingaporeRestrictedAnnex ACD Annex VI (Preservatives) #39
Chemical name
Mixture of 5-Chloro-2-methyl-isothiazol-3(2H)- one and 2-Methylisothiazol-3(2H)-one (INCI) / Methylchloroisothiazolinone (and) Methylisothiazolinone (9), 2682-20-4, 55965-84-9
CAS
26172-55-4
Max concentration
0,0015 %(of a mixture in the ratio 3:1 of 5-chloro- 2- methylisothiazol 3(2H)-one and 2-methylisothiazol-3 (2H)-one)
Conditions of use
Rinse-off products

Source: ASEAN Cosmetic Directive (HSA Dec 2025)

MalaysiaRestrictedAnnex ACD Annex VI (Preservatives) #39
Chemical name
Mixture of 5-Chloro-2-methyl-isothiazol-3(2H)- one and 2-Methylisothiazol-3(2H)-one (INCI) / Methylchloroisothiazolinone (and) Methylisothiazolinone (9), 2682-20-4, 55965-84-9
CAS
26172-55-4
Max concentration
0,0015 %(of a mixture in the ratio 3:1 of 5-chloro- 2- methylisothiazol 3(2H)-one and 2-methylisothiazol-3 (2H)-one)
Conditions of use
Rinse-off products

Source: ASEAN Cosmetic Directive (HSA Dec 2025)

ThailandRestrictedAnnex ACD Annex VI (Preservatives) #39
Chemical name
Mixture of 5-Chloro-2-methyl-isothiazol-3(2H)- one and 2-Methylisothiazol-3(2H)-one (INCI) / Methylchloroisothiazolinone (and) Methylisothiazolinone (9), 2682-20-4, 55965-84-9
CAS
26172-55-4
Max concentration
0,0015 %(of a mixture in the ratio 3:1 of 5-chloro- 2- methylisothiazol 3(2H)-one and 2-methylisothiazol-3 (2H)-one)
Conditions of use
Rinse-off products

Source: ASEAN Cosmetic Directive (HSA Dec 2025)

IndonesiaRestrictedAnnex ACD Annex VI (Preservatives) #39
Chemical name
Mixture of 5-Chloro-2-methyl-isothiazol-3(2H)- one and 2-Methylisothiazol-3(2H)-one (INCI) / Methylchloroisothiazolinone (and) Methylisothiazolinone (9), 2682-20-4, 55965-84-9
CAS
26172-55-4
Max concentration
0,0015 %(of a mixture in the ratio 3:1 of 5-chloro- 2- methylisothiazol 3(2H)-one and 2-methylisothiazol-3 (2H)-one)
Conditions of use
Rinse-off products

Source: ASEAN Cosmetic Directive (HSA Dec 2025)

VietnamRestrictedAnnex ACD Annex VI (Preservatives) #39
Chemical name
Mixture of 5-Chloro-2-methyl-isothiazol-3(2H)- one and 2-Methylisothiazol-3(2H)-one (INCI) / Methylchloroisothiazolinone (and) Methylisothiazolinone (9), 2682-20-4, 55965-84-9
CAS
26172-55-4
Max concentration
0,0015 %(of a mixture in the ratio 3:1 of 5-chloro- 2- methylisothiazol 3(2H)-one and 2-methylisothiazol-3 (2H)-one)
Conditions of use
Rinse-off products

Source: ASEAN Cosmetic Directive (HSA Dec 2025)

PhilippinesRestrictedAnnex ACD Annex VI (Preservatives) #39
Chemical name
Mixture of 5-Chloro-2-methyl-isothiazol-3(2H)- one and 2-Methylisothiazol-3(2H)-one (INCI) / Methylchloroisothiazolinone (and) Methylisothiazolinone (9), 2682-20-4, 55965-84-9
CAS
26172-55-4
Max concentration
0,0015 %(of a mixture in the ratio 3:1 of 5-chloro- 2- methylisothiazol 3(2H)-one and 2-methylisothiazol-3 (2H)-one)
Conditions of use
Rinse-off products

Source: ASEAN Cosmetic Directive (HSA Dec 2025)

GCC6 regulations
UAERestrictedAnnex V #39
Chemical name
Mixture of 5-Chloro-2-methyl-isothiazol-3(2H)-one and 2-Methylisothiazol-3(2H)-one with magnesium chloride and magnesium nitrate
CAS
26172-55-4, 2682-20-4, 55965-84-9
Max concentration
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
Product type
Rinse-off

Source: GSO 1943:2024 (based on EU 1223/2009 V)

Saudi ArabiaRestrictedAnnex V #39
Chemical name
Mixture of 5-Chloro-2-methyl-isothiazol-3(2H)-one and 2-Methylisothiazol-3(2H)-one with magnesium chloride and magnesium nitrate
CAS
26172-55-4, 2682-20-4, 55965-84-9
Max concentration
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
Product type
Rinse-off

Source: GSO 1943:2024 (based on EU 1223/2009 V)

QatarRestrictedAnnex V #39
Chemical name
Mixture of 5-Chloro-2-methyl-isothiazol-3(2H)-one and 2-Methylisothiazol-3(2H)-one with magnesium chloride and magnesium nitrate
CAS
26172-55-4, 2682-20-4, 55965-84-9
Max concentration
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
Product type
Rinse-off

Source: GSO 1943:2024 (based on EU 1223/2009 V)

OmanRestrictedAnnex V #39
Chemical name
Mixture of 5-Chloro-2-methyl-isothiazol-3(2H)-one and 2-Methylisothiazol-3(2H)-one with magnesium chloride and magnesium nitrate
CAS
26172-55-4, 2682-20-4, 55965-84-9
Max concentration
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
Product type
Rinse-off

Source: GSO 1943:2024 (based on EU 1223/2009 V)

KuwaitRestrictedAnnex V #39
Chemical name
Mixture of 5-Chloro-2-methyl-isothiazol-3(2H)-one and 2-Methylisothiazol-3(2H)-one with magnesium chloride and magnesium nitrate
CAS
26172-55-4, 2682-20-4, 55965-84-9
Max concentration
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
Product type
Rinse-off

Source: GSO 1943:2024 (based on EU 1223/2009 V)

BahrainRestrictedAnnex V #39
Chemical name
Mixture of 5-Chloro-2-methyl-isothiazol-3(2H)-one and 2-Methylisothiazol-3(2H)-one with magnesium chloride and magnesium nitrate
CAS
26172-55-4, 2682-20-4, 55965-84-9
Max concentration
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
Product type
Rinse-off

Source: GSO 1943:2024 (based on EU 1223/2009 V)

EAEUNo restrictions

No specific restrictions for METHYLCHLOROISOTHIAZOLINONE in Russia, Belarus, Kazakhstan, Armenia, Kyrgyzstan.

Frequently Asked Questions

Is METHYLCHLOROISOTHIAZOLINONE banned in any country?

METHYLCHLOROISOTHIAZOLINONE is not banned in any of the 26 markets tracked by Formpli. However, it may be subject to restrictions or conditions of use in some markets.

What are the restrictions on METHYLCHLOROISOTHIAZOLINONE in cosmetics?

METHYLCHLOROISOTHIAZOLINONE is restricted or has conditions of use in UAE, Australia, Bahrain, Brazil, Canada, European Union, Indonesia, Japan, South Korea, Kuwait, Malaysia, Oman, Philippines, Qatar, Saudi Arabia, Singapore, Thailand, Taiwan, United Kingdom, Vietnam. Restrictions may include maximum concentration limits, product type limitations, or mandatory labeling requirements. See the detailed regulations above for specifics.

Can I use METHYLCHLOROISOTHIAZOLINONE in cosmetics?

METHYLCHLOROISOTHIAZOLINONE is regulated in 20 markets. It has restrictions in UAE, Australia, Bahrain, Brazil, Canada, European Union, Indonesia, Japan, South Korea, Kuwait, Malaysia, Oman, Philippines, Qatar, Saudi Arabia, Singapore, Thailand, Taiwan, United Kingdom, Vietnam. Use Formpli's free screening tool to check your full ingredient list against all 26 markets at once.

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This information is for reference only and does not constitute legal or regulatory advice. Regulations change — always verify with official sources and consult a regulatory specialist before exporting cosmetic products. Data sourced from EU COSING, US FDA, Health Canada, MHLW Japan, MFDS Korea, ASEAN ACD, GCC SFDA, TGA Australia, ANVISA Brazil, EAEU TR CU, and Taiwan TFDA.