You must make sure drum sanders have one of the following to enclose that part of the drum not used to work on the material:
(1) Guard.
(2) Exhaust hood.
Reference:
Exhaust hoods are required on sanders when dust levels exceed exposure limits. See chapter 296-841 WAC, Airborne contaminants.
EXEMPTION:
When a table is used for the application of material to be finished, you do not need to enclose the portion of the drum above the table that is necessary to do the work.