QUESTIONHere in California, my 1978 counter-top consists of 6" tiles on a 3/4" mortar bed (w/metal mesh) sitting on tar paper on wooden boards. I would like to replace the cabinets, keeping the same design, and install a new quartz counter-top. I found that removing the tiles and crumbly mortar with a hammer and screw driver is do-able, but that the dust irritates my eyes. Now I am wondering if the dust contains the same silica produced by electric saws, drills and grinders, and if the amount is enough to be concerned about. I am contemplating doing the following:
(1) keep the mortar continuously wet with two Windex spray bottles,
(2) wear a full-face 3M respirator with P100 filters,
(3) hang 3.5 mil Home Depot plastic around my kitchen (using 1x2 boards),
(4) direct a fan out the window,
(5) rent an air scrubber from Sunbelt Rentals for $200/week.
Would any or all of this be a good idea or am I being paranoid? Thank you for your thoughts.
ANSWERANSWER - Last year OSHA issued rules to limit workers' exposure to respirable crystalline silica. The rule that went into effect on June 23, 2016 cuts the respirable silica PEL from 100ug/m3 for an 8-hour time weighted average to 50 ug/m3. If a work is going to be exposed to silica for 4 hours then they need to wear an APF 10 rated respirator. There is silica sand in tile grout, thin-sets and mortars.
Tile and stone industries are trying to get this OSHA ruling revised to be more reasonable. First of all it is difficult to measure exposure, and second of all it seems unlikely that the amount of exposure that installers are subjected to is considered unhealthy.
It is always wise to control dust for both health reasons and for cleanliness reasons. Installers typically use a wet/dry vacuum to collect the dust as they cut through concrete or mortar. They will wet down the mortar to control dust. They might put up some sheets of plastic containment to control the dust. They also wear at least a standard disposable dust mask. It would be better to use at least an APF 10 disposable N95 Industrial Respirator with Valve face mask that filters 95% of all particles like the 3M 8300 Series of disposable face mask respirators.
To control dust at a higher level you can build a portable containment barrier with a HEPA air filtration system, wear protective suites and full face mask filters. But that is normally used where they are mitigating microbial growth or or asbestos contaminates.