- Active (455)
- Anti-irritant (111)
- Antimicrobial (90)
- Antioxidant (15)
- Colorant/Pigment/Hair Dye (91)
- Conditioner/Moisturizer (238)
- Delivery (150)
- Exfoliant (11)
- Feel Enhancer (172)
- Film-former (11)
- Formulating Aids (129)
- Fragrance (72)
- Preservatives (71)
- Repair (95)
- Rheology/Viscosity Modifier (82)
- Surfactant/Emulsifier (132)
- UV Filter (104)
Build a solid foundation in science, formulation and product development—find out more!
Most Popular in:
Exclusive! Comparatively Speaking: Bacteriostatic vs. Bacteriocidal by Tony O'Lenick
Posted: June 20, 2006
Industry expert Tony O’Lenick explains the difference between a bacteriostatic and bacteriocidal.
Bacteriostatic and bacteriocidal are both terms that relate to microbial growth. They are antimicrobials that include anti-bacterial, anti-viral, anti-fungal and anti-parasitic compounds. Bacteriostatic and bacteriocidal differ from each other by how they affect the bacteria.
A bacteriostat is a compound that keeps bacteria from reproducing. It does not kill bacteria if they are already present, but it keeps their number from increasing. A bactericide, on the other hand, is a compound that kills bacteria. If a product already is contaminated with bacteria, the addition of a bacteriostat may slow the growth but will not kill the existing bacteria. To kill existing bacteria, a bactericide must be added.
The concept of selective toxicity is important here; in cosmetic formulations, one generally wants a compound that kills bacteria and fungi without causing harm to the human using it. Cyanide, for example, is a very effective bacteriocidal compound but it does not make a good additive to cosmetic products since it also is quite toxic to the person using it.