Ingredient
Methylisothiazolinone
What is Methylisothiazolinone?
Methylisothiazolinone is a chemical compound used as a preservative. It is commonly found in personal care products, household cleaners, and industrial settings to prevent the growth of bacteria and fungi. It is synthesized through a series of chemical reactions involving formaldehyde, cyanide, and other compounds.
This preservative is favored for its effectiveness in low concentrations and its broad-spectrum antimicrobial properties. However, there has been concern regarding its potential to cause allergic reactions, particularly skin irritations. The evidence is mixed, with some studies pointing to significant risks for sensitive individuals.
When you see methylisothiazolinone on a label, it's important to recognize that it is added to extend the shelf life of products. Those with sensitive skin or known allergies should approach products containing it with caution.
Commonly found in: sunscreen, shampoos, lotions, liquid soaps, dishwasher detergents, household cleaners
What to watch
- Linked to skin allergies, especially in leave-on products.
- Potential for causing inflammatory skin reactions in sensitive individuals.
The FDA does not specifically regulate methylisothiazolinone by itself in cosmetics but emphasizes labeling for consumer awareness.
Research indicates a risk of skin sensitization, though some studies show it is safe in rinse-off formulations.
Methylisothiazolinone is a synthetic preservative and is not derived from animal sources, making it suitable for vegan use.
Sources: Safety Assessment of Methylisothiazolinone as Used in Cosmetics
Scout's take
Severe contact allergen. American Contact Dermatitis Society named MI 'Contact Allergen of the Year' in 2013. EU restricts in leave-on cosmetics.
The case against
Methylisothiazolinone can cause skin sensitization, allergic reactions, and irritation.
from the analysis of Sun Bum Signature SPF 30 Lotion · echoed in 1 other analysisThe case for
It prevents microbial growth, extending the product's shelf life.
from the analysis of Seventh Generation Liquid Laundry Detergent - Free & Clear - 90 fl ozIt provides effective preservation against microbial growth.
from the analysis of Sun Bum Signature SPF 30 LotionMore from Scout's analyses
Methylisothiazolinone is used as a preservative in cosmetics. It is effective at preventing microbial growth but is known to cause skin sensitization and allergic reactions. It is often criticized for its potential to cause skin irritation and allergic reactions.
from the analysis of Sun Bum Signature SPF 30 LotionMethylisothiazolinone is a preservative that can cause skin sensitization and allergic reactions in some individuals. It is also considered an aquatic toxin, raising concerns about its environmental impact.
from the analysis of Safely Multi-Surface Cleaning Wipes CalmMethylisothiazolinone is a preservative used to prevent microbial growth. It is known to cause skin sensitization and allergic reactions. Its potential for causing skin issues makes it less desirable.
from the analysis of Seventh Generation Liquid Laundry Detergent - Free & Clear - 90 fl ozFound in 6 products
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