Attaching a normal shop vacuum to a dust-collecting circular saw can remove 81% of dangerous silica dust from the air, the National Institute for Occupational Safety and Health (NIOSH) reported today.

The federal agency said its "practical solution" reduces exposure to crystalline silica to well below NIOSH recommendations. It also made these recommendations:

  • Use a shop vacuum with an air-flow rate of 30 CFM or higher with a hose connected to the circular saw.
  • The hose used to connect the shop vacuum and circular saw should be 1.25 inches or greater in diameter and should be only as long as necessary and be kept straight.
  • A high efficiency disposable filter bag can be used as a pre-filter in the shop vacuum to capture most of the dust.
  • The shop vacuum and circular saw can be plugged into an intelligent vacuum switch, which turns on and off the vacuum and ensures the vacuum is running while operating the saw, avoiding uncontrolled dust release. For shop vacuums that don’t have the switch incorporated in it, an aftermarket device with the same feature can be purchased and used.
  • Use only circular saws with a built-in dust collection container or shroud that functions as a hood, partially encloses the saw blade, and can easily connect to a shop vacuum.
  • Use polycrystalline diamond-tipped (PCD) blades designed for cutting fiber-cement siding.

A potential change to OSHA rules regarding silica has been widely discussed over the past few years. Trade associations have come out against it, insiders have weighed in, and more clarifications have been asked for

OSHA is expected to make a decision on the new silica dust rule sometime before President Obama leaves office in January 2017. Read more about NIOSH's self-styled "practical solution" here. And leave a note in the comments telling us your thoughts on the OSHA rule and whether you've ever used a shop-vac and dust-collection saw before.