Silica Awareness PPT-SM-SILICA 2014

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1 Silica Awareness 1

2 Silica Every year, over 1 million workers are exposed to silica dust Over 250 workers die from silica inhalation every year Hundreds more are severely disabled 2

3 Silica Silica is the mineral silicon dioxide (SiO 2 ) Three types of rock contain silica 1.Quartz Most common rock in Earth s crust 2. Cristobalite 3. Tridymite When ground, these rocks produce a dust that carries silica The finely ground dust is known as silica flour 3

4 Silica Dust Silica dust can be found in numerous industrial operations Hydraulic fracturing (fracking) and sandblasting The sand used in fracking and sandblasting contains up to 99% silica Abrasives such as sandpaper and grinding and polishing agents Drilling, crushing, loading, hauling, and dumping of rock 4

5 Silica Dust Silica dust can be found in numerous industrial operations Abrasively blasting, sawing, chipping, drilling, and grinding concrete and brick Dry sweeping or air blowing concrete, rock or sand dust 5

6 Silica Dust Silica dust can also be found in numerous materials used in the oil and gas industry Scouring powders Metal polishes Paints Rubber Paper Plastics Wood fillers Cement Road surfacing materials Foundry applications 6

7 Silica-related Health Hazards Inhaled or ingested silica causes serious lung damage and lung disease Travels through your airways into your lungs Inhaled silica particles damage your lungs This damage causes scar tissue to develop, narrowing and eventually blocking your airways over time Inhaled silica particles can also damage the DNA in your cells, causing cancer 7

8 Silica-related Health Hazards Diseases linked to silica exposure include Lung cancer Chronic Obstructive Pulmonary Disorder (COPD) Tuberculosis (TB) Scleroderma Renal disease Silicosis Autoimmune disease Kidney disease 8

9 Silicosis Workers exposed to silica may develop silicosis, an incurable lung disease A silicosis patient s x-ray Healthy lung Silicosis patient s lung 9

10 Silicosis Silicosis is a progressive, disabling, and often fatal lung disease Symptoms include Shortness of breath Fever Fatigue Loss of appetite Chest pain Dry, nonproductive cough Respiratory failure 10

11 Silicosis Types of silicosis Chronic silicosis Results from silica exposure over time Usually occurs after 10 or more years of exposure to relatively low silica concentrations Accelerated silicosis Results from exposure to high concentrations of silica Usually develops 5-10 years after exposure to very high concentrations of silica Acute silicosis Develops from exposure to highest concentrations to silica Symptoms can develop anywhere from a few weeks later to 4-5 years after first exposure 11

12 Permissible Exposure Limits NIOSH Recommended Exposure Limit (REL) = 0.05 mg/m 3 Immediately dangerous to life and health (IDLH) limit IDLH = 25 mg/m 3 for cristobalite and tridymite IDLH = 50 mg/m 3 for quartz and Tripoli OSHA 12

13 OSHA Guidelines Employers must Provide information and training about silica to workers Medically monitor workers who are exposed to silica dust levels at or above half of the PEL Monitor silica in the air by collecting samples Control dust exposures through engineering and safe work practices Provide respiratory protection to workers 13

14 OSHA Guidelines Employers must Reduce employee exposure by limiting work involving silica dust Supply vacuums with HEPA air filters Report all cases of silicosis to state health departments and record cases on OSHA logs Post warning signs to identify work areas where respirable silica is present 14

15 NIOSH Recommendations Get a medical examination before starting work and receive a follow-up exam every three years Conduct frequent air monitoring Blast-clean machines and cabinets Use wet drilling or wet sawing Use local exhaust ventilation When drilling rock, use water through the drill stem When sawing concrete or masonry use saws that provide water to the blade 15

16 NIOSH Recommendations Remove dust from equipment using a water hose rather than compressed air Practice good personal hygiene Wash hands often, remove PPE after work, shower and change clothes before leaving work, etc. Wear disposable or washable protective clothing Post warning signs around silica-contaminated work areas 16

17 NIOSH Recommendations Condition Minimum respiratory protection required to meet the NIOSH REL (0.05 mg/m 3 ) < 0.5 mg/m 3 * (10 x REL) Any half-mask, air-purifying respirator with a high-efficiency particulate (HEPA) filter 0.5 mg/m 3* (10 x REL) 1.25 mg/m 3 (25 x REL) 2.5 mg/m 3 (50 x REL) 50 mg/m 3 (1,000 x REL) 100 mg/m 3 (2,000 x REL) Planned or emergency entry into environments containing unknown concentrations or concentrations >100 mg/m 3 (2,000 x REL) Firefighting Escape only Any half-mask, air-purifying respirator with a HEPA filter Any powered, air-purifying respirator with a HEPA filter, or any supplied-air respirator (SAR) equipped with a hood or helmet and operated in a continuous-flow mode Any air-purifying, full-facepiece respirator with a HEPA filter, or any powered, air-purifying respirator with a tight-fitting facepiece and a HEPA filter Any SAR equipped with a half-mask and operated in a pressure-demand or other positive-pressure mode Any SAR equipped with a full facepiece and operated in a pressure-demand or other positive-pressure mode (for example, a Type CE abrasive-blasting respirator operated in a positive-pressure mode) Any self-contained breathing apparatus (SCBA) equipped with a full facepiece and operated in a pressuredemand or other positive-pressure mode, or any SAR equipped with a full facepiece and operated in a pressure-demand or other positive-pressure mode in combination with an auxiliary SCBA operated in a pressure-demand or other positive-pressure mode. Any SCBA equipped with a full facepiece and operated in a pressure-demand or other positive-pressure mode Any air-purifying, full-facepiece respirator with a HEPA filter, or any appropriate escape-type SCBA

18 Control Methods Workers and employers must work together to prevent silica exposure Remove dust by using a water hose, a vacuum, or by wet sweeping Explore alternatives to crystalline silica for abrasive blasting Wear respiratory protection Remain clean shaven when wearing respirators 18

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