indicating membership in an association of hygienists

reference books, training manuals, textbooks, guide books, handbooks, workbooks, newsletters, bulletins, and monographs, all in one or more of the fields of industrial, occupational and environmental hygiene, safety and health; toxicology; medicine; hazardous materials and waste; workplace controls; hazardous physical agents; ergonomics; laboratory/quality control; and professional development of industrial, occupational and environmental hygienists