In some cases, workers exposed to low levels of silica dust over a long period develop silicosis (chronic silicosis). However, new information is showing that workers exposed to high levels of silica dust for several months may also be at risk.
Employers are required to protect workers from being exposed to more than 50 micrograms of respirable silica per cubic meter of air (50 µg/m3) during an 8-hour work day, as per safety guidelines by the Occupational Safety and Health Administration (OSHA).