Process equipment and water system contamination from microbes protected within a biofilm continues to affect production schedules and product quality.
Multiple critical parameters exist for disinfection of hard surfaces. These include: biocidal agent, biocide concentration, contact time, contact temperature, microbial population and type, soil level, surface characteristics, water quality and other factors.
In this series of studies, the authors examined how various surfaces and micro-organism types affected the ability to disinfect and clean biofilms.
Cleaning and disinfection efficacy were evaluated using TOC analysis, visual cleanliness and microbial efficacy testing.
The surfaces that were examined included EPDM rubber, PTFE Teflon, Buna rubber and UMHW polyethylene. US Centers for Disease Control (CDC) reactors were used to develop a Pseudomonas aeruginosa biofilm on coupons made of each surface type according to ASTM E2562-12.
The ASTM E2871-13 single tube method was followed for harvesting biofilm and testing biofilm coated coupons using a formulated alkaline detergent at 1% (v/v) and a formulated hydrogen peroxide/peracetic acid ready to use (RTU) sterilant at 20% (v/v).
The cleaning procedure utilised a low action immersion cleaning method and swabbing technique for measurement of total organic carbon (TOC) before and after biocidal agent contact.
The results illustrated that for biofilm contamination, surface type was not the most significant contributing factor in disinfectant efficacy.
Not yet a Subscriber?
This is a small extract of the full article which is available ONLY to premium content subscribers. Click below to get premium content on Manufacturing Chemist.
Subscribe now Already a subscriber? Sign in here.