Propylparaben

Propylparaben (CAS 94-13-3, molecular formula C10H12O3, molecular weight 180.20) is a white crystalline powder at room temperature, melting at 95-98°C, with an assay (on dried basis) of 99.0-100.5 and an acidity pH of 4.0-7.0 (see specifications). It dissolves readily in ethanol and ether, with slight solubility in boiling water and near-zero solubility in cold water. According to published literature, propylparaben shows higher antimicrobial activity than the methyl and ethyl esters, with growth inhibition against Gram-positive and Gram-negative bacteria, molds and yeasts; the applicable pH range is 4-8, and it is often combined with other parabens. Actual dosage follows formulation verification and the target market's current regulations; some markets (e.g. the EU) restrict its use in cosmetics by concentration limits and scope (per current regulations of the target market).

Used in cosmetics and personal care as a preservative and antimicrobial agent, reported active against Gram-positive and Gram-negative bacteria, molds and yeasts. Downstream applications include creams, lotions, shampoos and cleansers; finished-product shelf life is subject to the buyer's preservative challenge testing. Propylparaben has higher antimicrobial activity than methyl and ethyl parabens, and is often combined with other parabens. Applicable pH range 4–8; actual dosage follows formulation verification and the target market's current regulations; some markets (e.g. the EU) restrict its use in cosmetics by concentration limits and scope (per current regulations of the target market).

Shampoos, body washes and cleansing products are a common application direction for propylparaben (see Usage); preservation of surfactant systems commonly relies on ester blends, with this product serving as the antimicrobial component and system fit verified in the formulation. Since it is practically insoluble in cold water, alcohol pre-dispersion is recommended before addition.

In emulsified and semi-emulsified products such as creams and lotions, propylparaben serves as a preservative component; per published literature its antimicrobial activity is higher than that of the methyl and ethyl esters, and it is often used in blends. Actual use follows formulation verification and the target market's current regulations; some markets (e.g. the EU) restrict its use in cosmetics by concentration limits and scope (per current regulations of the target market).

Propylparaben is often combined with other parabens (see Usage); planned blend partners and ratios can be provided at inquiry and checked against the specifications on this page (assay 99.0-100.5, melting point 95-98°C).