OSHA chief David Michaels put two related regulatory concerns -- a pending rule to tighten controls on crystalline silica dust and the agency's worry about antiquated chemical permissible exposure limits -- at the centerpiece of a push on Friday (April 25) for tougher OSHA protections ahead of Workers Memorial Day, April 28, sounding alarms about what he calls a host of “silent killers” rampant in the workplace.
