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From:		Chet Fenton, Carlie Knope, and Dan Ertis, Eastern Research Group, Inc.
To:		Bryan Lincoln, Robert Stone, Tiffany Defoe, and Tom Mockler, OSHA DSG
Subject:	Summary of ERG Interviews on Abrasive Blasters' Use of Beryllium Blast Media
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At OSHA's request, ERG has interviewed three people familiar with the abrasive blasting industry to assess the frequency with which abrasive blasters use beryllium blast media (coal and copper slag). ERG also asked these interviewees about how patterns of usage vary by industry, the makeup of work crews, and the current use of respirators. Their responses are summarized below.

   1. What percent of abrasive blasters use beryllium (coal and copper slag) and non-beryllium blast media?
Specific estimates of what percentage of abrasive blasters use coal and copper slag ranged from around 50 percent (Respondent C) to 80 to 90 percent (Respondent B).  The respondents also provided a qualitative assessment of the predominance of coal and copper slag. Respondent A noted that the "overwhelming majority of abrasive blasting done in construction contexts uses coal slag," and Respondent B added that, "all abrasive blasters will at some point use coal and/or copper slag products."
   2. Of those blasters who use coal and copper slag, how often do they use that type of material vs. other types of material?
Of those blasters using coal and copper slag, Respondent B suggests such media are used 50 to 90 percent of the time, depending on but not limited to factors such as environmental conditions (moisture, temperature, etc.) and substrate type. Respondent A concurs, noting, "The share of substrates represented by materials too soft for coal slag is quite small" (put, at one point in the conversation, at 15-20 percent of blasting jobs). Though not providing an estimate, Respondent C mentioned "most contractors/blasters tend to find a medium they like and stick with it."
   3. Does this vary in construction as compared to shipyards?
Both Respondent A and Respondent C stated that abrasive blasting practices were consistent between construction and industrial marine applications, with Respondent A elaborating further that, "DOT and government contracts [i.e., municipal infrastructure, Naval shipyards, etc.] prohibit the use of [silica] sand, and coal slag is what's used instead." Respondent B says the use of beryllium blast media differs between construction and shipyards, "depend[ing] upon specifications."
   4. Are there any other patterns in the type of blast media used (e.g., for bridges vs. buildings, or certain surfaces)?

All three Respondents agree substrate density informs abrasive blast media choice. For example, Respondent A notes you would not use steel shot on aluminum siding. Citing substrate fragility, it is unlikely that buildings are regularly blasted, but denser surfaces such as oil tanks and pipes (coal slag) or bridges (steel shot) will often receive treatment (Respondent A and Respondent B, respectively).  Other factors such as "disposal concerns and biodegradability" (Respondent B), "municipal regulations," and simply owner specification (Respondent C) also shape blast media use patterns.
   5. How many helpers are there per blaster?
The number of helpers per blaster depends mostly on the project (e.g., oil tanks usually take around four cleanup crew whereas Midwest bridges may require 20 blasters and 40 cleanup crew), with the general ratio being one or more helpers and two cleanup crew for every blaster (Respondent A). Other conditions factor in, as well, and Respondent B places the average between one to four helpers per blaster. 
An additional data point comes from RS Means (2011), a construction cost estimation database. RS Means lists a standard blasting crew as consisting of two structural steel painters (most likely the blasters themselves, with duties also including coating application and painting), one building laborer (i.e., helper), and one light equipment operator (most likely the air compressor operator) for a job blasting 1,000 square feet per day using sand.
   6. How often do blasters use supplied air respirators?
Respondent A said that blasters currently use APF 1,000 blasting hoods. Respondent B estimates that blasters use supplied air respirators 95 to 100 percent of the time, but recognizes the exposure risk extends beyond the time spent actively blasting. Respondent C states, "respirators should be used all the time" and notes that blasting technician certification involves checking clean-air respirators. 
   7. What kind of respiratory gear do blasting helpers and cleanup people wear?
Respondents provided a variety of answers to this question. They ranged from Respondent C's submission that "everyone on the job site (including helpers) should wear respirators" to Respondent A's assertion that "helpers and cleaners don't use respirators" and use "at most, a cloth mask." Respondent A also mentioned that other workers around abrasive blasting operations (e.g., painters or inspectors) are unlikely to use any respiratory gear at all. Respondent B described how the type of respirator use varies over the course of the job: "During blast operations, in the same environment as the blasters, supplied air respirators are used. Outside containment and/or after blast operations cease, depending upon exposure assessments, respirators range from half air purifying respirators to full face air purifying respirators." 

                                  References

Respondent A. Telephone Calls between Respondent A and ERG. September 18 and 23, 2014.

Respondent B. Email from Respondent B to ERG. September 19, 2014.

Respondent C. Telephone Call between Respondent C and ERG. October 2, 2014. October 2, 2014.

RS Means, 2011. Building Construction Cost Data 69th Annual Ed. Reed Construction Data, Inc.
