The Influence of Changes in Concentration and Temperature upon the Bactericidal Activity of Formaldehyde in Aqueous Solutions
Although formaldehyde in aqueous solution (formalin) is an important and widely used disinfectant, there is very little information available concerning the exact effect of changes in either concentration or temperature upon its bactericidal activity. An experimental study was therefore made of the bactericidal activity of formaldehyde. This study was conducted along the lines of previous studies of the bactericidal activities of phenols and alcohols (Tilley, 1939, 1942).
Sporostatic and Sporocidal Properties of Aqueous Formaldehyde
Aqueous formaldehyde is shown to exert both sporostatic and sporocidal effects on Bacillus subtilis spores. The sporostatic effect is a result of the reversible inhibition of spore germination occasioned by aqueous formaldehyde; the sporocidal effect is due to temperature-dependent inactivation of these spores in aqueous formaldehyde. The physicochemical state of formaldehyde in solution provides a framework with which to interpret both the sporostatic and sporocidal properties of aqueous formaldehyde.
Enumeration of total coliforms, fecal coliforms, and Escherichia coli in foods by hydrophobic grid membrane filter: supplementary report.
Raw, comminuted poultry meat was used to determine the specificity of the media and incubation conditions used in the hydrophobic grid membrane filter method. Confirmation rates for target colonies were 100% for total coliforms, 98% for fecal coliforms, and 97-99% for Escherichia coli. The results of total coliform enumeration in 30 pasteurized milk samples by both the hydrophobic grid membrane filter method and AOAC method 46.013-46.016 are also reported.