4/18/2018 What is silica? Respirable Crystalline Silica Its Not Just Dust! One of the most common Photos courtesy PDPhoto.org minerals on Earth Concern: 3 forms of crystalline silica Silica is found in rock, soil, and sand Quartz — common, found in sand, gravel, clay, granite, sandstone and eLCOSH images other rock Cristobalite and Tridymite — Photo courtesy PDPhoto.org Photo: CPWR less common, but more toxic to workers Photo: CPWR These materials may contain silica How can you find out if it contains silica? o Asphalt o Refractory Mortar/Castables Product label o Brick o Refractory units o Cement o Rock Safety Data Sheet o Concrete o Roof tile (concrete) Published data — online o Concrete block o Sand o Drywall Analyze a sample of the o Soil (fill dirt, top soil, soil w/fly ash o Fiber cement products (siding, material added) cladding panels) o Stone (granite, limestone, quartzite, o Grout sandstone, shale, slate, cultured, etc.) o Mortar o Stucco/EIFS o Paints o Terrazzo o Plaster o Tile (clay and ceramic) 1
4/18/2018 Size matters! Silica Hazards “Respirable” silica is small enough to penetrate body’s Why is silica a natural defenses and get deep into your lungs hazard? Crystalline Silica Photo source: CDC It’s 100 times smaller than ordinary beach wikimedia sand How Small is Small? Silicosis Respirable Dust, e.g., Lead, Silica & A lower case 'o' when Asbestos (<10 µm) printed in Times New Roman size 10 (1mm). Large Dog Human Hair (80 – 120 µm) The respirable silica dust 1 m enters the lungs and causes 1 cm the formation of scar tissues, o thus reducing the lungs' .000001 .001 0.01 0 1 ability to take in oxygen. Micron (µm) Millimeter (mm) Centimeter (cm) Meter (m) Photo: OSHA What can it do to you? o Silicosis o Lung cancer o Chronic obstructive pulmonary disease ( COPD) o Immune system effects o Kidney effects Are these effects Chronic or Acute? 2
4/18/2018 Silicosis Facts Stop Silicosis - 1938 o Inhalation of respirable crystalline silica particles has long been known to cause silicosis, a ✓ Permanent disabling, non-reversible and ✓ Irreversible sometimes fatal lung disease ✓ No cure The Hawk's Nest Tunnel Disaster — ✓ Worsens after exposure 1930 — 700 to over 1000 deaths ends Silicotic Lung Normal Lung ✓ Deadly Photo: CDC Preventing exposure is your best defense Putting it all together When will I find dust? Silica is hazardous because: Long-time exposure o Manufacturing: Foundries, Abrasive blasting, Paint, to small amounts Silica dust Found in many causes harm Glass, Concrete, Brick making, Plumbing fixtures, travels deep construction into your lungs Refractory, Mixing (dry), Grout and Caulking materials Short-time o Construction: highway, masonry, concrete, rock exposure to Airborne drilling, cleaning up large amounts particles too causes harm o Construction tasks : masonry saws, grinders, drills, small to see jackhammers and handheld powered chipping tools; vehicle-mounted drilling rigs; milling; operating Causes lung Effects worse if you also smoke disease, cancer, crushing machines; and heavy equipment for eLCOSH Images even death demolition. eLCOSH images OSHA OSHA Respirable Crystalline Silica Respirable Crystalline Silica (RCS) Rule Permissible Exposure Levels (PELs) o Two standards: Action Level = 25 micrograms per cubic meter of air o One for general industry and maritime (25 µg/m 3 ) calculated as 8-hour TWA o One for construction o Similar to other OSHA Substance Specific Health Standards PEL = 50 micrograms per cubic meter of air (50 µg/m 3 ) averaged over an 8-hour day What does that mean? 3
4/18/2018 Construction Standard, 1926.1153 Industry Standard, 29 CFR, 1910.1053 (a) Scope (b) Definitions (c) Specified exposure control methods (Table 1) o DEFINITIONS – PARAGRAPH (B) OF THE STANDARD OR o PERMISSIBLE EXPOSURE LIMIT (PEL) – PARAGRAPH (C) (d) Alternative exposure control methods o EXPOSURE ASSESSMENT – PARAGRAPH (D) (1) PEL o REGULATED AREAS – PARAGRAPH (E) >PEL (2) Exposure Assessment o METHODS OF COMPLIANCE – PARAGRAPH (F) (3) Methods of Compliance • Engineering and Work Practice Controls >PEL (e) Respiratory protection, Required by Table 1 or >PEL for Alternative • Written Exposure Control Plan All covered employers o RESPIRATORY PROTECTION – PARAGRAPH (G) >PEL (f) Housekeeping, All covered employers avoid certain practices o HOUSEKEEPING – PARAGRAPH (H) All covered employers, avoid certain practices (g) Written exposure control plan, All covered employers o MEDICAL SURVEILLANCE – PARAGRAPH (I) >PEL >30 days/year through 6/22/2020 (h) Medical surveillance, Wear a respirator ≥ 30 days/year then AL (i) Communication of silica hazards, All covered employers o COMMUNICATION OF HAZARDS – PARAGRAPH (J) All covered employers (j) Recordkeeping o RECORDKEEPING – PARAGRAPH (K) (k) Dates Exposure Assessment Silica Sampling Personal Breathing Zone Silica Sampling • Crystalline silica: respirable fraction is of concern due to the health effects o Sample for respirable particulate OSHA PEL: 50 µg/m 3 = 0.05 mg/m 3 RCS Standard – Scope o All occupational exposures to respirable crystalline silica are covered, unless employee exposure will remain below 25 μg/m 3 as an 8-hr TWA under any foreseeable conditions. o The phrase “any foreseeable conditions” refers to situations that can reasonably be anticipated, for example, failure of engineering Respirable silica dust equivalent to controls <0.1% of a sweetener packet over the course of an 8 hour workday o Therefore, employers who maintain exposures below 25 µg/m 3 16.8 m 3 would exceed the OSHA PEL of with engineering controls are covered. 50 µg/m 3 . 4
4/18/2018 Silica Exposure Determination RCS Exposure Assessment o Initial assessment o Objective Data • Not required if objective data of exposure <AL of 25 µg/m 3 • Plumbers, carpenters, and electricians who have to drill a hole are exempted — <15 minutes o Scheduled Monitoring option — Periodic IH moniting • Construction tasks exempted also includes pouring concrete or removing forms • < AL Discontinue o Performance Option • > AL < PEL – every six months o Scheduled Monitoring Option — IH Monitoring • > PEL – every 3 months o Utilize Table 1, (Construction Only) o Performance option – assess exposure for each employee sufficient to • Fully and properly implemented characterize exposures • Do not have to assess employees’ silica exposure levels or keep employee exposures at or o Reassess below the permissible exposure limit (PEL) Performance Option Objective Data o Exposures assessed using any combination of air monitoring data o Includes air monitoring data from industry-wide surveys or objective data sufficient to accurately characterize employee or calculations based on the composition of a substance exposure to respirable crystalline silica o Demonstrates employee exposure associated with a particular product or material or a specific process, task, o Be able to demonstrate that employee exposures have been or activity accurately characterized o Must reflect workplace conditions closely resembling or with a higher exposure potential than the processes, types of material, control methods, work practices, and o Reassess exposures whenever a change may reasonably be environmental conditions in the employer's current expected to result in new or higher exposures at or above the operations action level Employee Notification of Assessment Roadmap for meeting the Construction Requirements Results of the Respirable Crystalline Silica Standard o Within 15 working days after completing an exposure assessment; o Determine if the silica standard applies to your employees • Employer shall individually notify each affected employee in writing of the results. • Not required if objective data of exposure <AL of 25 µg/m 3 • Required if employees could be exposed to RCS at or above 25 µg/m 3 as • Employer can post results in appropriate location accessible to all affected employees. an 8-hour TWA under any foreseeable conditions, including the failure of • If exposures exceed the PEL, the employer shall describe in writing the corrective action engineering controls being taken to reduce exposures. o Choose to comply with the standard using either the: • Observation of monitoring • Specified exposure control methods in Table 1, or o Affected employees or their designated reps have the option to observe the air • The alternative methods of compliance monitoring. (similar to General Industry) o Observers must comply with the PPE requirements of the area. » Schedule Monitoring Option » Performance Option 5
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