Review of questionnaire to AIHA accredited laboratories for the analysis of silica

X-ray powder diffraction is one of the two principal methods used for the routine analysis of free SiO2 for monitoring silica in the industrial workplace. During late 1996 and early 1997, a questionnaire was prepared and distributed to all the analytical laboratories on the American Industrial Hygiene Association (AIHA) list of accredited facilities that indicated they did analyses for silica. This report is based on the responses to that questionnaire with comments from the author on the responses and recommendations that suggest themselves from the responses.