Documented Test Results: Dust Director?, Dust Collector? Vacuum.

Test 1. Dust Director’s? Effectiveness in Controlling Silica Dust,

by IMI – International Masonry Institute and CPWR – Center To Protect Workers’ Rights, October 2001

The following test results were based on a study conducted at the BAC (Bricklayers and Allied Craftworkers’) Apprentice Training Center in Bordentown, NJ, by IMI and CPWR (the safety and health arm of the AFL-CIO’s Building and Construction Trades Department).

The study compared and evaluated various Controlled and Uncontrolled Masonry Tasks and Tools and their effectiveness in capturing or containing silica dust particles in a work environment.

The table below shows the computer measured test results from the study.

The Dust Director was the only dust control tool that stood out: Not only was the Dust Director effective in containing the silica dust but, its results were better than the dust control system that used water in controlling the dust.

Tool / Task


Severity Ratio *


Time (Minutes)

Angle Grinder Dry

Without using the Dust

Using 4″ x .250

Mortar between

57 times over
the PEL



Grinder Dry Grinding

Using the Dust Director

4″ x .250 Diamond Blade

between bricks

1.2 times
over the PEL



Dry Cutting w/
Masonry Portable Saw (12″ blade)

Block / Brick

48 times over
the PEL



Wet Cutting w a
Stationary Wet Saw (14″ blade)

Block / Brick

1.1 times over
the PEL



Documented Results on the Dust Director? System:

  • Published Test Results,
  • Test Results “below” the NIOSH’s established PEL,
  • Worker Approved: “A tool they will use and continue to use . . . even when I turn my back.” — Safety Director, Restoration & Waterproofing Contractor, St. Louis, MO.

Test 2. Dust Collector? Professional Vacuum Effectiveness in Containing Silica Dust,

by Center To Protect Workers’ Rights (CPWR) and International Masonry Institute (IMI) Local 5, Bordentown, NJ – Silica Dust Grinding Samples – Respirable Silica, May 8 – 10, 2006

The following test results are sampling done to date on the controls for tuck pointing. Of the vacuums tested, silica dust exposures were reduced by 86 – 94%.

“Ted Segiel will be happy to hear that his latest vacuum (the Dust Collector? Professional showed the greatest reduction at 94%.”

“Another thing to note, without the use of the an actual dust control tool (i.e. dustless guard), exposures were over 100 time the NIOSH PEL (Permissible Exposure Limit) for Silica. OSHA PEL (Permissible Exposure Limit) were over 50 times the limit.”

“If these were full 8 hour shifts, even with respirators with an assigned protection factor of 10, workers would be over exposed relative to the permissible exposure limit.

“So point being: respirators may be used to supplement engineering controls, but certainly are not sufficient alone to ensure compliance with OSHA regulations.”

The table below shows the computer measured test results from the study.

Tool / Control


Dry Cutting

a 4″ x .250 diamond blade

Mean Over the PEL

% Reduction

Angle Grinder

without Dust Controls

106 Xs


Metabo Angle

Using the Dust

With the Dust
Collector? Professional Vacuum

8 Xs


Up Next: Silica Dust Controls: Before and After Pictures