TL;DR: it's already regulated (by OSHA). Total number of deaths annually by silicosis in the US is low (~15/year). The workers need to file an OSHA complaint if they haven't already.
I don´t know the wikipedia page mention "must provide" which in my opinion is not enough and should be must enforce.
the OSHA page (https://www.osha.gov/laws-regs/regulations/standardnumber/19...) mention "the employer shall fully and properly implement the engineering controls, work practices, and respiratory protection specified for the task on Table 1" which one could read as more than just need to provide but I have idea if it's true.
As for the death tool which seem low it's not so good when take into account the number of worker (from the article):
> In California, workplace safety regulators have estimated that out of roughly 4,000 workers in the industry across the state, silicosis will afflict between 485 and 848 — and that as many as 161 could ultimately die
https://en.wikipedia.org/wiki/Silicosis#Regulation_in_the_US
TL;DR: it's already regulated (by OSHA). Total number of deaths annually by silicosis in the US is low (~15/year). The workers need to file an OSHA complaint if they haven't already.