Testing wash water at produce packing operations isn’t rocket science, but it should be done in a scientific manner with the key to success being attention to details, food safety experts say.

However, sweating the details doesn’t mean testing and dosing has to be complicated. Simple can be better than complex, especially for smaller growers, said Trevor Suslow, a researcher at the University of California-Davis Extension Service, and farm food safety coach Jim Hollyer, from the University of Hawaii-Manoa.

Hollyer and Suslow recently answered frequently asked questions about produce wash water during a web seminar sponsored by the Center for Produce Safety at UC-Davis.

Simple details key for wash waterTips from Suslow included resisting the temptation to use expired test strips, instead using kits that are designed to perform a single test, instead of multi-test kits that he said are notoriously inaccurate. Suslow stressed the importance of diligence in recording test results in a food safety log.

“It doesn’t have to be a complicated form that takes a lot of time,” Suslow said. “But it should include things that could be pertinent during an inspection or audit.”

That includes the date and time of testing, the name of the person doing the test, test results and any action taken as a result of testing.

Suslow said smaller operations do not need to invest in electronic hand-held testers or fancy titration kits and chlorination gizmos: test strips that usually cost 17 cents to 20 cents are perfectly acceptable, provided they are not expired and the package instructions are followed.

Simple details key for wash waterSuslow and Hollyer said common sense can go a long way when it comes to wash water in packing operations.

One of the most frequently asked questions they receive is when to change wash water. There are tests, but one rule of thumb is as simple as it gets: if it looks dirty, it probably is.

Hollyer said even though human eyes cannot see pathogens or other microscopic contaminants in wash water, they can see when it is cloudy or loaded with particulates.

“You can’t ignore what you see,” Hollyer said. “You could bring in clean (produce) from the field and if your wash water is dirty it will contaminate the produce.”

Hollyer said simple measures such as paying attention to wash water sources, following instructions on test kits and using sanitizing agents can help maintain effective food safety.