Po
Polyquaternium-39
Polyquaternium-39
A polymer that reduces static, forms a film and helps hold hair in place.
What it does
It’s a large polymer with a positive charge, so it clings to hair and skin.
The evidence, graded
expert consensusUS safety reviewers (2016) assessed polyquaternium-22 and polyquaternium-39, polymers that products use to cut static, form a film and hold hair in place. Polyquaternium-39 was used at up to 3%. Leftover acrylamide from making it was a concern, but at under 1 ppm it keeps products well below the reviewers’ limit. Tests showed little potential to irritate skin or cause allergy, and as large, highly polar molecules they’re unlikely to be absorbed. They judged both safe as used.Johnson 2016 · International Journal of Toxicology ↗
Graded per the methodology: strong · moderate · emerging · expert consensus. A weak source on a strong claim gets the weaker label.
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