Healthy skin has a slightly acidic pH, typically between 5.5 and 6.5. High-quality facial cleansers, especially those suitable for sensitive and acne-prone skin, should have a stable pH within the slightly acidic range of 5.5-6.0 to match the skin's environment and reduce irritation. Cleansers with a pH that is too alkaline (>7) tej zaum yuav ua rau daim tawv nqaij puas tsuaj nrog kev siv sijhawm ntev -.
Cov npuas dej hauv lub ntsej muag yog tsim los ntawm surfactants reacts nrog dej thiab huab cua los ntawm kev sib txhuam. Lub luag haujlwm ntawm ua npuas ncauj yog rub thiab nqus cov av ntawm daim tawv nqaij saum npoo, thaum tseem dispersing cov surfactants. Tus nqi ntawm cov npuas dej tsis cuam tshuam ncaj qha rau cov nyhuv ntxuav; nws nyob ntawm hom surfactant thiab cov mis. Foaming cleansers (siab-foaming) feem ntau muab cov nyhuv cleansing muaj zog thiab haum rau oily daim tawv nqaij; lotion-type, low-foaming, los yog non-foaming cleansers feem ntau softer thiab haum rau cov tawv nqaij qhuav thiab rhiab heev.
Raws li cov qauv tsim, cov khoom siv ntxuav tuaj yeem muab faib ua cov tshuaj ntxuav tes, ntxuav cov gels, ntxuav cov foams, ntxuav cov tshuaj pleev, thiab cov hmoov ntxuav, thiab lwm yam.