Last week the Occupational Safety and Health Administration (OSHA) finalized their rules for workers who are exposed to silica dust, which workers can breathe in and develop cancers or other diseases.

This rule will significantly lower the acceptable levels of silica dust workers can be exposed to, from 250 micrograms per cubic meter of air for construction workers and 100 micrograms for other industries, to 50 micrograms for all industries. This cap will hopefully protect workers against the hazards of silica dust.

Beyond the limited exposure levels employers will also have to actively reduce exposure, common ways to do this are by using water or ventilation systems to keep dust from getting out into the air where it can be inhaled. They will need to provide workers with protective equipment if they cannot use water or ventilation controls. They will have to give employees who work in high-exposure areas medical exams. Employers have until June of 2018 to come into compliance with the new rules, but construction industry employers have to be compliant by June of 2017.

Silica dust can cause silicosis, a kind of incurable lung cancer, chronic obstructive pulmonary disease and other respiratory issues. The dust is common in construction sites and sites that cut or drill concrete, stone, and bricks containing silica. Hydraulic fracturing, glass manufacturing, pottery or jewelry making, or oil and gas work can also create this dust. There are millions of people who work in those industries. OSHA estimates that every year 600 people die from silica related illnesses, and they think 900 people are newly diagnosed with silica related illnesses every year. These new rules are estimated to save $7.7 billion a year.

The exposure limits had not been altered since 1971.

“The previous exposure limits were outdated and did not adequately protect workers,” said the Assistant Secretary of Labor for OSHA, Dr. David Michaels.

Industry groups have said they disagree with the new limits and that the cost to businesses would be much higher than estimated.