[Inactivation of formaldehyde by semicarbazide in disinfectant tests with viruses].

In suspension tests with viruses formaldehyde is--even in weak concentrations--toxic for tissue cultures. Through addition of semicarbazide in a ratio of one part of 10% semicarbazide to one part of 0.7% formaldehyde, which is equivalent to a molar ratio of 3.8:1, the toxicity will be neutralized if semicarbazide is added to the tissue cultures before their being inoculated with the virus-disinfectant-mixture. In qualitative experiments the toxicity is completely neutralized, in quantitative ones it is reduced by a factor of 10 up to 100. Thus the evaluation of the virucidal capacity of disinfectants containing formaldehyde is conspicuously improved.