Factors Affecting Efficacy of Sanitizers

i. Physical Factors

Surface Characteristics : All equipment surfaces must be thoroughly clean prior to sanitization. Since the effectiveness of sanitization requires direct contact with the microorganisms, the surface should be free of cracks, pits, or services, which can harbor microorganisms. Surfaces which contain biofilms (films formed by the ability of microorganisms to attach and grow on food and food-contact surfaces under favorable conditions) cannot be effectively sanitized.

Exposure Time : In general, the longer time a sanitizer chemical is in contact with the equipment surface, the more effective the sanitization effect; intimate contact is as important as prolonged contact.

Temperature : Temperature is positively related to microbial destruction by a chemical sanitizer. Owing to the corrosive nature of most chemical sanitizers, high temperatures (about 55° C) should be avoided.

Concentration : Although the activity of a sanitizer increases with the increased concentration in general, it is always best to study the properties of the chemical before using it. Employing sanitizer concentrations above recommendations can be corrosive to equipment and in the long run lead to less cleanliness.

Soil : The presence of organic matter dramatically reduces the activity of sanitizers and may, in fact, totally inactivate them.

 

ii. Chemical Factors

pH : Sanitizers are affected by the pH of the solution. Many chlorine sanitizers,for example, are almost ineffective at pH values above 7.5.

Water properties : Certain detergent residues contain inactivators that react chemically with sanitizers giving rise to non-germicidal products. Thus, it is important that surfaces be rinsed prior to sanitization.

 

iii. Biological Factors

The microbiological load can affect sanitizer activity. The type of microorganisms present can also influence the effectiveness of sanitizer. Sanitizers also vary in their effectiveness against yeasts, mold, fungi and viruses. Certain sanitizers are more active against gram positive than gram-negative microorganisms and vice versa.Spores are more resistant than vegetative cells.