USA: change in proficiency testing fields for environmental laboratories

From 1 January 2026 the proficiency testing tables for non-potable water replace gamma-chlordane with trans-chlordane.

2026-01-01

In the American system proficiency testing is a condition for keeping accreditation, so a change in the table changes the laboratory participation plan.
The swap concerns organochlorine pesticides: the analyte, its code and its registry number change, and so do the quality system records.
Separately, changes to the tables for whole effluent toxicity testing were announced, taking effect in mid-May 2026.