November 26, 2018
With the OSHA regulation (1926.1153 – Respirable crystalline silica. | Occupational Safety and Health Administration) on silica, installers need to be aware of the proper vacuum systems used, especially with the 4” and 7” grinders and saws.
The dust collector (vacuum) must provide 25 cubic feet per minute (CFM) or greater of airflow per inch of wheel diameter and have a filter with 99% or greater efficiency and cyclonic pre-separator or filter-cleaning mechanism.
What this means is the vacuum for a 7 inch cup wheel needs to be minimum 175 CFM.
At this time the vacuum is not required to have a HEPA filter on it when attached to the grinder along with the appropriate shroud. However, when using the vacuum for cleaning it must have a HEPA filter.
Check with your equipment supplier to make sure the CFM and efficiency numbers are at the appropriate level for the equipment you are using. Currently, this regulation applies only to hand held equipment.