Bioluminescence testing for rapid detection of microbial contamination in aqueous polymer emulsions

• The validated ATP protocol is a reliable method for detecting microbial contamination in aqueous polymer emulsions.
• The validated ATP protocol can distinguish between a clean sample from a microbially contaminated aqueous polymer emulsions.
• The validated ATP protocol can be used in a wide range of chemistries of aqueous polymer emulsions.
• The validated ATP test allows microbial detection in aqueous polymer emulsion immediately before shipping to the customer.

Most aqueous polymer emulsions (APE) used in coatings applications are susceptible to microbial spoilage, which can result in loss of application properties for the end customer. A spoiled batch can potentially cost $50,000 - $250,000; an estimate that does not necessarily include the cost of product replacement, remediation and disposal in addition to labor and other ancillary costs.Early detection of microbes in APE prior to shipment can reduce this risk. Normally, the typical test method requires 24–72 h to detect most microbial species. Moreover, some species need as many as 7–9 days of incubation for detection, and others might not be detected at all. With these traditional methods, by the time contamination is detected at the manufacturing plant, the material may have already been delivered to a customer. We have validated a reliable and easy-to-use bioluminescence test for microbial detection in most APE. The bioluminescence test is a rapid method for quantification of living cells based on the detection of the molecule adenosine triphosphate or ATP. We found the method to be easy to execute with repeatable results. It also has a good correlation with our standard method and results are obtained in less than an hour. This is the first report on the successful use of ATP detection to assess the microbial quality of APE in the coatings industry. Having a process that facilitates real-time detection, along with triggering immediate action will reduce the risk of delivering contaminated material and reworking costs. This is expected to improve the overall performance of manufacturing plants.