Silica- Clearing the Air Scott Schneider, MS, CIH Director of Occupational Safety and Health Laborers Health and Safety Fund of North America

Silica is not a new problem In 1700, Bernardino Ramazinni published a book on occupational diseases and recognized respiratory diseases among stone cutters In 1910, Alice Hamilton studied silica exposures among granite workers in Vermont In 1938, Congress was outraged when over 400 workers died of acute silicosis at the Gauley Bridge tunnel job in West Virginia

Francis Perkins 1938

Acting to Stop Silicosis Francis Perkins, Secretary of Labor, in 1938 convened a National Conference to Stop Silicosis In 1974, NIOSH recommends dramatic reductions in the silica exposure limit to 50 micrograms/cubic meter and a comprehensive standard Robert Reich, Secretary of Labor, in 1997, began a campaign with NIOSH Its Not Just Dust and holds a National Conference to Eliminate Silicosis In 2006, ACGIH recommends an even lower exposure limit, 25 micrograms/cubic meter

History of OSHA efforts OSHA publishes an Advanced Notice of Proposed Rulemaking on whether it should adopt the NIOSH recommended standard for silica (with 0.05 mg/m3 REL) PEL Update- OSHA modernizes the PEL for Silica to mg/m3 but this rulemaking is thrown out by the courts OSHA places silica standard on reg agenda as long term action OSHA expects to propose a new silica standard by June Current PEL measurement method is labeled obsolete OSHA completes Small Business panel review OSHA completes Peer Review of Health Effects data June OSHA expects to publish Proposed Silica Standard

Health Effects of Silica Reported deaths from silicosis have dropped to about 150 a year But many cases go unreported: 8.5% of NJ blue collar workers from dust- exposed industries who had underlying lung disease listed on their death certificate had undetected silicosis on autopsy A Michigan study estimated about 3,600- 7,300 new cases of silicosis each year in the US We have known for about 30 years that silica exposure also causes cancer In 1997 IARC designated silica as a human carcinogen Lung cancer from silica exposures probably outnumber silicosis cases Silica causes other forms of respiratory disease as well Awareness of the hazard is low because construction tends to be dusty and effects are chronic

Worksafe BC Video

Exposures and Controls Silica exposures from construction operations can be very high, e.g. from tuck pointing and abrasive blasting But exposures can be easily and inexpensively controlled using water or local exhaust Many studies have been published in the past 10 years showing % exposure reduction More tools are now coming equipped with controls Some States (NJ, CA) have banned dry cutting and have not experienced any compliance problems

Dry Cutting is Risky Business

Wet vs. Dry Cutting

OSHA Publication on Controlling Silica in Construction

NIOSH Information products Spanish versions

NIOSH engineering control page with control videos tructionControlMain.html Without dust controls Dust suppression with water

Dust Control Solutions Simple Solutions book from Arbouw in The Netherlands 2002 Includes criteria for purchasing equipment with controls

Dust Controls can help with productivity as well

The OSHA Proposal The draft reviewed by SBREFA in 2003 contained the following elements: Lowered PEL- 3 choices Modernize measurement method from mppcf to mg/m3 Table 1 specifies controls for high exposure tasks These elements have been designed specifically to make it easy for small businesses so they dont have to do a lot of expensive air monitoring

Table 1- Required Controls

Its About Time Silica has long been a health problem in construction The Government has been trying to regulate it for almost 30 years There are easy and inexpensive controls available Its finally time to get to work and protect workers from this serious hazard