[About the temperature dependence of the bactericidal effect of some chemical disinfectants (author's transl)]

In quantitative suspension tests the influence of different temperatures (4 degrees C, 12 degrees C, 22 degrees C, 37 degrees C, +/- 2 degrees) on the bactericidal effect of formalin, phenol, sodium hydroxide peracetic acid with respect to gram-positive and gram-negative test germs (10(8) KBE/ml original culture) was examined. The results showed for formalin, phenol and sodium hydroxide a distinct temperature factor within the range of the germ-dependent, bactericidal limit concentrations. Compared with the temperature of about 22 degrees C which is normally applied in disinfectants tests revealed that at 12 degrees C the action time had at least to be doubled and at 4 degrees C the action time had to be four times as long for the complete killing of the germs. By contrast, with peracetic acid in its minimum effective concentrations (0.015 to 0.06%) a total germ reduction was attained after identical action times (5 minutes) at temperatures ranging between 4 degrees and 37 degrees C. Recommendations for the use of disinfectants must make allowance for the temperature factor.