What trigger language term in S500 and S520 suggests advised or suggested actions?

The term "recommended" in the context of the S500 and S520 standards indicates advised or suggested actions. This term is used to guide professionals in making choices about remediation practices based on best practices and accepted industry standards. It conveys a level of flexibility, suggesting that while the action is beneficial and endorsed by the guidelines, it may not be mandatory, allowing professionals to exercise their judgment based on the specific circumstances they encounter.

The other terms, such as "should," "shall," and "must," establish different levels of obligation. "Should" implies a recommendation that is generally expected to be followed but leaves room for exceptions. "Shall" and "must," on the other hand, are used to denote requirements that must be adhered to, indicating that failure to comply with those directives could result in negative consequences or liability. Therefore, "recommended" uniquely captures the essence of advice without imposing a strict obligation, aligning with practices common in the field of microbial remediation.