Inactivated by organic materials.
Anionic agents .Soaps and fatty acids
It causes gross work.
disruption of cell membrane
. More active in Gram-positive bacteria than in Gram-negative
bacteria. . Active at acidic PH
Phenolic compounds Phenol is highly effective in Gram positive bacteria. Clinically no more used because of its neurotoxic effect. Currently used as a standard for measuring bactericidal potency of new chemicals i.e. phenol coefficient. Phenol coefficient is the ratio of the concentration of the new chemical agent being tested to the concentration of the reference standard (phenol) required to kill in a specific time. If phenol coefficient is less than one, the new chemical agent is less effective than phenol. If phenol coefficient is equal to one, the new chemical agent is equal to phenol in efficacy. If phenol coefficient is more than one, the new chemical agent is more effective than phenol. Derivatives of phenol:
. Cresols e.g. Lysol, Creolin . Halogenated diphenyl compounds eg. Hexachlorophene It is more active on Gram-positive bacteria. It is germicidal and anti-perspirant.