Safety Knights

The mastic helps to contain the fine bits of aggregate, which is where the silica is found. I’d be really surprised if jackhammering asphalt would cause an overexposure. If you were sawing or grinding, then that would be a different story.

Does it have silica? Yes, so therefore it would fall under Table 1 ("Jackhammers and handheld powered chipping tools"). As you will note from Table 1, as long as you're implementing engineering controls mentioned in Table 1, respiratory protection is only required in specific situations. The key words related to your question are in the 2nd half of this statement:

"1926.1153(c)(1)
For each employee engaged in a task identified on Table 1, the employer shall fully and properly implement the engineering controls, work practices, and respiratory protection specified for the task on Table 1, UNLESS the employer assesses and limits the exposure of the employee to respirable crystalline silica in accordance with paragraph (d) of this section."

I was at a VPP site in North Caroline (Bridgestone Manufacturing), which my previous employer had multiple millwrights, welders, etc. on site. During this project, Bridgestone had OSHA's VPP consultants come out and essentially audit all of their contractors. One of the topics of discussion (which Rick knows this, as well) is forklift operators in the areas. The VPP consultants told us we needed to do an exposure assessment on our telehandler operators to ensure they weren't being exposed over the action level or PEL - even though we knew it would be little to no exposure). So to your question, although the exposure may be minimal during those tasks, since they are specifically listed in Table 1, you either have to implement the required controls mentioned in Table 1, including specific requirements of 1926.1153(c)(2), OR you can just have sampling done to verify the actual exposure levels.

Here's a good research article from 2016 that discusses this very topic. It focuses on milling, rather than jackhammering/chipping, but does talk about the content of respirable crystalline silica.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4915055/# :~:text=The%20silica%20content%20in%20the,roads%20milled%20by%20Manufacturer%20B.

Yes. Though, most cases, not an overexposure situation. There are regional differences in aggregate to keep in mind depending on the required spec of the road. Roads may have different lifts designed for increased tensile strengths. Couple that with geographic differences in the aggregate and you will find that different parts of the country deal with varying concentrations of silica in asphalt. Also, it’s a good idea to check the materials you are hammering as you go. While not common that I’ve seen, you can run into different materials through a repair/replacement which obviously provides potential increases in silica exposures. Probably more so in FDR work but then, you probably wouldn’t be hammering at that point. Great question.