Quaternium-15

Quaternium-15 (CAS 51229-78-8), also sold under trade names Dowicil 200, DOWICIL, and Pycal 94, is a quaternary ammonium chloride compound that functions as a formaldehyde-releasing preservative. It is classified under the broader surfactants category and carries no assigned E-code.

In rinse-off and leave-on personal care formulations, Quaternium-15 inhibits microbial growth by releasing formaldehyde at controlled rates, disrupting bacterial cell function. In water-based coatings and adhesive systems, it prevents spoilage during storage by maintaining effective biocide concentrations across a broad pH range.

Quaternium-15 is supplied as a solid and is subject to REACH registration requirements within the EU. Formulators should note restrictions under EU Cosmetics Regulation 1223/2009, which limits its use and mandates labelling when formaldehyde release exceeds 0.05%. Procurement teams should confirm supplier documentation including Safety Data Sheets and Certificate of Analysis for each batch.