America is catching up with the UK on exposure limits to respirable crystaline silica (RCS) dust in the manufacture of worktops and other stone products.

America's equivalent of the UK's Health & Safety Executive, the Occupational Safety & Health Administration (OSHA), along with its National Institute for Occupational Safety & Health (NIOSH), has issued an advisory health alert on countertops production and crystalline-silica exposure that is an indication of tighter regulation to come.

The advisory limits are the same as in the UK – 0.1mg of RCS per cubic metre of air.

Industry groups, including the Marble Institute of America (MIA) were consulted by OSHA and NIOSH prior to release of the health advisory.

Jim Hieb, CEO and executive vice president of the Marble Institute of America, said: “The hazard alert is fairly balanced because they did consult the industry, but we are all, obviously, very anxious to hear the news on the rule change and we’re being proactive with this through numerous coalitions. We’re fortunate we were consulted on this.”

The seven-page alert from OSHA and NIOSH offers details on why silica exposure is a concern for the countertop trade and recommends lowering exposure levels (mainly through ventilation and wet production).

The alert warns about the danger of processing stone such as granite, quartzite, sandstone, slate and soapstone. A table in the alert notes granite’s silica content as 10%-45% while in engineered quartz surfaces it is greater than 93%.

Workers who inhale crystalline silica particles of around the 5micron size are at risk of silicosis. Symptoms of silicosis can include shortness of breath, cough and fatigue. It puts people at increased risk of killers such as lung cancer, chronic obstructive pulmonary disease and kidney disease.

Even the 0.1mg/m³ exposure level accepts that some people will suffer from silicosis and die of cancer. There is no safe level of exposure and breathing any amounts of RCS should be avoided. The American stone processors' organisations are being proactive in tackling the issue.

You can read the American OSHA/NIOSH report here...