ASTM E645 – Antimicrobial Test – Cooling Water

ASTM E645 is an antimicrobial multi-cycle challenge test that exposes a microbicide, either alone or as formulated with standard industrial water systems, to a series of common microbial contaminates.

ASTM E645 testing is commonly used for microbicides as found in cooling water systems, industrial uses such as manufacturing, production a sanitization, as well as in water-based products where microbial growth may impact the quality of the water source, industrial process, or end- product.

This antimicrobial test method demonstrates the effects that representative microbes have on microbicides commonly seen in actual use – opening and closing of the container, vat, or pipe, and the constant inoculation of the biocide-treated water source with environmental organisms or organisms commonly associated with standard industrial processes.

Evaluation and testing can provide important data about a microbicides performance while in use in a cooling water system.

Typically tested to standard bacteria and fungal challenges, ASTM E645 is often modified to include specific organisms, depending on the needs of the end-customer.

Options include a wide range of bacteria, fungi, and algal cultures as well as custom time-points and cycle lengths.

Once exposed to microbial populations, the ability of the preservative to withstand initial contact and subsequent re-inoculations helps to determine the effectiveness of a particular preservation system and/or formulation.

For more information about ASTM E645, contact our antimicrobial lab at 847-483-9950 or

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