Amended Safety Assessment of Methylisothiazolinone as Used in Cosmetics

Abstract

The Expert Panel for Cosmetic Ingredient Safety (Panel) reassessed the safety of Methylisothiazolinone, which functions as a preservative in cosmetics. The Panel reviewed relevant animal and human data provided in this safety assessment, and data from the previously published safety assessments of Methylisothiazolinone, and concluded that Methylisothiazolinone is safe for use in rinse-off cosmetic products at concentrations up to 100 ppm (ie, 0.01%) and safe in leave-on cosmetic products when they are formulated to be nonsensitizing, which may be determined based on a quantitative risk assessment or similar methodology.

Contact Dermatitis Associated With Hair Care Products: A Retrospective Analysis of the North American Contact Dermatitis Group Data, 2001–2016

“…28 According to the Cosmetic Ingredient Review Expert Panel, in 2014, 190 uses of MI in noncoloring HCPs were reported to the Food and Drug Administration Voluntary Cosmetic Registration Program, accounting for 25.5% (190/745) of all reported cosmetic uses of MI. 29 We found that shampoos/conditioners were associated with the highest proportion of MI reactions. Shampoo-related MI contact allergy has been well established in the literature in both adults and children.…”

“…Shampoo-related MI contact allergy has been well established in the literature in both adults and children. 27,[29][30][31][32] The concentration of MI and contact time may determine tolerance in rinse-off products; Frosch et al 33 assessed 27 MCI/MI-sensitized patients and found that most (75%) were able to tolerate shampoo containing MCI/MI.…”

Isothiazolinones Common in Children's Toy Slime

“…2 However, these concentrations are well below reported sensitization and elicitation thresholds for MI in particular (~500 and ~50 ppm, respectively), suggesting that colorimetric test false-negatives are unlikely to be clinically significant. 27 The identification of isothiazolinones in commercial slime products is salient, given the complex regulation surrounding the toy industry that does not mandate declaration of toy ingredients, in stark contrast to the regulation of cosmetic products. With the marked popularity of slime, major glue companies have created dedicated website and products for use in slime preparation, all without labels identifying which items contain isothiazolinones.…”

“…None of the commercial slime products tested in this study had ingredient labels. The United States mandates that leave-on cosmetic products have a nonsensitizing MI content based on quantitative risk assessment and that rinse-off products have 100 ppm or less of MI 27,28 ; this raises the question: should children's toys like slime be considered a leave-on product as children often play for hours without washing their hands?…”

Quality assessment of baby wet wipes

“…Currently, safety testing is accomplished via animal test models, non-animal in vitro test models, and clinical human subject testing. 29 Common methods used to assess the tolerability of wipes are repeated insult patch test (RIPT) to control allergy and irritation, cumulative irritation test (CIT) to control irritation, phototoxicity/photoallergy (PT/PA) to control photoallergy (UV-induced) and irritation, ocular installation to control eye irritation, and safety-in-use to control suitability. 19 Manufacturing complexities of baby wet wipes are frequent and include the water quality, the converting processes, the folding configurations, the stack orientation, the packaging formats, and especially the lotion formulation.…”