Table 1

Summary of particle filtration efficiency testing results

Mask testedTesting condition
0.25 µm0.5 µm
 Batch 1Not tested*Passed
 Batch 2FailedFailed
 Batch 3PassedPassed
US-manufacturedPassedNot tested
  • The US-manufactured mask successfully filtered out particles of 0.25 µm. Of the three batches of the foreign-manufactured masks, batch #2 failed to filter out 0.25 µm and 0.5 µm particles.

  • *Note that 0.25 µm microspheres were not tested in batch #1 since we used up our available supply at the time.