As to the collaboration, the managers were asked by the
team of researchers after occupational health education to
continue supporting the workers to use personal protective
equipment at both the assembly section and other sections.
The managers permitted the workers to join in all steps of
this research. The workers willingly participated in this
research and collaborated with managers on that. However,
they were not obligated to use the mask (3M, 9322). They
could change the mask, if they found its decreased efficacy
or its defect.