Silica Awareness PPT-SM-SILICA 1 2014
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 PPT-SM-SILICA 2 2014
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” PPT-SM-SILICA 3 2014
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 PPT-SM-SILICA 4 2014
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 PPT-SM-SILICA 5 2014
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 • PPT-SM-SILICA 6 2014
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 PPT-SM-SILICA 7 2014
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 PPT-SM-SILICA 8 2014
Silicosis Workers exposed to silica may develop silicosis, an incurable lung disease Healthy lung Silicosis patient’s lung A silicosis patient’s x-ray PPT-SM-SILICA 9 2014
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 PPT-SM-SILICA 10 2014
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 PPT-SM-SILICA 11 2014
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 PPT-SM-SILICA 12 2014
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 PPT-SM-SILICA 13 2014
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 PPT-SM-SILICA 14 2014
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 PPT-SM-SILICA 15 2014
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 PPT-SM-SILICA 16 2014
NIOSH Recommendations 3 ) Condition Minimum respiratory protection required to meet the NIOSH REL (0.05 mg/m 3 * (10 x REL) < 0.5 mg/m Any half-mask, air-purifying respirator with a high-efficiency particulate (HEPA) filter 3* (10 x REL) ≤ 0.5 mg/m Any half-mask, air-purifying respirator with a HEPA filter 3 (25 x REL) ≤ 1.25 mg/m 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 3 (50 x REL) ≤ 2.5 mg/m 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 3 (1,000 x REL) ≤ 50 mg/m Any SAR equipped with a half-mask and operated in a pressure-demand or other positive-pressure mode 3 (2,000 x REL) ≤ 100 mg/m 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) Planned or emergency entry into Any self-contained breathing apparatus (SCBA) equipped with a full facepiece and operated in a pressure- environments containing unknown demand or other positive-pressure mode, or any SAR equipped with a full facepiece and operated in a concentrations or concentrations pressure-demand or other positive-pressure mode in combination with an auxiliary SCBA operated in a 3 (2,000 x REL) >100 mg/m pressure-demand or other positive-pressure mode. Firefighting Any SCBA equipped with a full facepiece and operated in a pressure-demand or other positive-pressure mode Escape only Any air-purifying, full-facepiece respirator with a HEPA filter, or any appropriate escape-type SCBA PPT-SM-SILICA 2014
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 PPT-SM-SILICA 18 2014
PPT-SM-SILICA 19 2014
Recommend
More recommend
