In addition to the existing test “damp heat steady state” an annex is planned to be published which describes specific humidity robustness grades and requirements for applications, where high stability under high humidity operating conditions is required. The Grades are:
Grade (I) robustness under humidity
Grade (II) robustness under high humidity
Grade (III) high robustness under high humidity
For verification manufacturer can choose between two test conditions:
Test condition A: Test damp heat, steady state; 40 °C / 93 % RH duration 21 days, rated voltage applied
Test condition B: Test damp heat, steady state; 85 °C / 85 % RH duration 168 h, rated voltage applied.
Test condition B is by the way a substitutional acceleration test for test condition A. Further info can be taken out of 60384-14 Amd.1 Ed.4.0.