Methylchloroisothiazolinone
IUPAC name	5-Chlor-2-methyl-4-isothiazolin-3-one
Other names	Chloromethylisothiazolinone; Chloromethylisothiazolone; Methylchloroisothiazolinone; Methylchloroisothiazolone; CMI; CMIT; MCI
Identifiers
CAS number	26172-55-4 Y
SMILES	S1N(C)C(=O)C=C1[Cl]
Properties
Molecular formula	C4H4ClNOS
Molar mass	149.59 g/mol
Appearance	colorless liquid
Density	1.02 g/cm³, liquid
Solubility in water	miscible with
Hazards
R-phrases	R23/24/25 R34 R43 R50/53
S-phrases	(S2) S26 S28 S36/37/39 S45 S60 S61
Y (what is this?)  (verify) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Methylchloroisothiazolinone (5-chloro-2-methyl-4-isothiazolin-3-one) is a preservative with antibacterial and antifungal effects within the group of isothiazolinones. It is effective against gram-positive and gram-negative bacteria, yeast and fungi.

Methylchloroisothiazolinone is found in many water-based personal care products and cosmetics.^[1] Methylchloroisothiazolinone was first used in cosmetics in the 1970s.It is also used in glue production, detergents, paints, fuels and other industrial processes. Methylchloroisothiazolinone is known by the registered tradename Kathon CG when used in combination with methylisothiazolinone.^[2]

Methylchloroisothiazolinone may be used in combination with other preservatives including ethylparaben, benzalkonium chloride or 2-bromo-2-nitropropane-1,3-diol.

[edit] Safety

In pure form or in high concentrations, methylchloroisothiazolinone can be a skin and membrane irritant or cause chemical burns. It was largely removed from most cosmetic products except for those with only short duration skin contact such as rinse-offs. Its inclusion in certain forms makes it more acceptable to sensitive users, so it can be found in cosmetic creams and lotions which require skin contact. In the United States, accepted concentrations are 15 ppm in rinse-offs and 8 ppm in other cosmetics.^{[citation needed]}

The International Agency for Research on Cancer (IARC), does not list methylchloroisothiazolinone as a known, probable or possible human carcinogen^[3], nor have in vivo tests found evidence of carcinogenic activity. Methylchloroisothiazolinone is an allergen for 1.7% of individuals.^[4]

[edit] References

1. ^ Reinhard et al.: "Preservation of products with MCI/MI in Switzerland". Contact Dermatitis. 2001 Nov;45(5):257-64. PMID 11722483
2. ^ Knudsen BB, Menne T: "Kathon CG--a new contact sensitizing preservative". Ugeskr Laeger. 1990 Mar 5;152(10):656-7. PMID 2321281
3. ^ International Agency for Research on Cancer Complete List of Agents evaluated and their classification, IARC (updated November 2007). Accessed January 7th 2008
4. ^ Zoller L, Bergman R, Weltfriend S. (2006). "Preservatives sensitivity in Israel: a 10-year overview (1995-2004)". Contact Dermatitis 55 (4): 227-9. PMID 16958921. 

[edit] External links

• Record in the Household Products Database of NLM

This chemical is often used in shampoos and conditioners or in the 2 in 1 mixes (e.g. Wash'n' Go.)