Presented By: Kary S. Amin
Definition of an Indoor Air Quality (IAQ) Problem: Air quality adversely affects building occupants
Acceptable IAQ Air in which there are not known contaminants at harmful concentrations as determined by cognizant authorities and with which a substantial majority (80% or more) of the people exposed do not express dissatisfaction ASHRAE Standard Standard 62.1 2016, Ventilation for Acceptable Indoor Air Quality
Is IAQ a new issue? In the construction of buildings, whether for public purposes or as dwellings, care should be taken to provide good ventilation and plenty of sunlight schoolrooms are often faulty in this respect. Neglect of proper ventilation is responsible for much of the drowsiness and dullness that make the teachers work toilsome and ineffective
1871
Why is Indoor Air Quality (IAQ) becoming an increasingly important issue in the construction industry? Building occupants becoming more aware of IAQ issues Building occupants experiencing more IAQ symptoms Construction schedules becoming more aggressive Contractors and trade employees are more conscience of environmental hazards
Four factors which affect IAQ: Pollutant sources HVAC system Pollutant pathways Building occupants
Four potential causes of IAQ problems during Construction: Component demolition that releases toxic materials or mold Construction dust and fumes Designs that interfere with ventilation Off-gassing from building materials and new products
Asbestos Lead Mold Volatile Organic Compounds (VOCs) Construction Dust Fumes
1. Potential health effects and symptoms associated with mold exposure include allergic reactions, asthma and other respiratory complaints. 2. There is no practical way to eliminate all mold and mold spores in the indoor environment; the way to control mold growth is to control moisture.
3. If mold is a problem, you must clean up the mold and eliminate sources of moisture. 4. Fix the source of the water problem or leak to prevent mold growth. 5. Reduce indoor humidity (to 30%-60%) to decrease mold growth by: Venting bathrooms, dryers and other moisture generating sources to the outside Using air conditioners and de-humidifiers Increasing ventilation Using exhaust fans
6. Clean and dry any damp or wet building materials and furnishings within 24 hours to prevent mold growth. 7. Clean mold off hard surfaces and dry completely. Absorbent materials such as ceiling tiles, that are moldy, may need to be replaced.
8. Prevent condensation: Reduce the potential for condensation on cold surfaces (i.e. windows, piping, exterior walls, roof or floors) by adding insulation. 9. In areas where there is a perpetual moisture problem, do not install carpeting. 10. Molds can be found almost anywhere; they can grow on virtually any substance, providing moisture is present.
Demolition that releases toxic materials or mold Construction dust and fumes Designs that interfere with ventilation Off-gassing from building materials and new products
Isolate HVAC Enclosure/Isolation Work Area Access/Security Negative Pressure Environmental Sampling
Common mineral that is found in materials that we see every day in roads, buildings and sidewalks. It is a common component of sand, stone, rock, concrete, brick, block and mortar, (quartz, cristobalite and tridymite).
Exposures to crystalline silica dust can occur in common workplace operations involving cutting, sawing, drilling and crushing of: Concrete Brick Block Rock Stone
Exposures from operations using sand products, such as Glass Manufacturing Foundries Sand Blasting Hydraulic Fracturing
Have known about silica hazards for over 80 years; OSHA s Permissible Exposure Limit was more than 40 years old; Clear evidence that previous exposure limits did not adequately protect worker s health. Epidemiological studies suggest that, at previous PEL, respirable crystalline silica exposure has been found to cause lung cancer and kidney disease; Many employers were already implementing necessary measures to protect workers from silica exposure.
Approximately 2.3 million people in the US are exposed to silica at work, (majority in construction). OSHA estimates that new silica standards will save the lives of more than 600 workers each year. OSHA estimates that new silica standards will prevent more than 900 cases of silicosis each year once full effects of rules are implemented.
General Industry/Maritime Standard (29 CFR Part 1910.1053) Covers general industry such as brick manufacturing, foundries and hydraulic fracturing (fracking). Effective June 23, 2016, fully implemented by June 23, 2018. For fracking, fully implemented by June 23, 2018, except engineering control provisions, compliance date is June 23, 2021. Construction Industry (29 CFR Part 1926.1053) Covers construction industry, those who drill, cut, crush or grind silica containing materials. Effective June 23, 2016, fully implemented by June 23, 2017
Regardless of exposure, employers are required to: Establish and implement a written exposure control plan Identifies tasks that involve exposure and methods used to protect workers including procedures to restrict access to work areas where high exposures may occur; Designate a competent person Responsible for implementing the written exposure control plan; Restrict Housekeeping Activities Control practices that expose workers to silica where feasible alternatives are available; Offer Medical exams Including chest e-rays and lung function tests every three years for worker who are required by the standard to wear respirators for 30 or more days per year;
Train workers Work operations that result in silica exposure and ways to limit exposure; Keep records Documentation on worker s silica exposure and medical exams.
Action Level Concentration of airborne respirable crystalline silica of 25 micrograms per cubic meter (µg/m³) based on an 8-hour TWA. Competent Person Individual who is capable of identifying existing and foreseeable respirable crystalline silica hazards in the workplace and who has authorization to take prompt corrective measures to eliminate or minimize them. Permissible Exposure Limit (PEL) Concentration of airborne respirable crystalline silica of 50 µg/m³ based on an 8-hour TWA.
Respirable crystalline silica are very small particles typically at least 100 times smaller than ordinary sand found on beaches or playgrounds. Caused by high energy operations like cutting, sawing, grinding, drilling and crushing stone, rock, concrete, brick, block and mortar.
Classified as a human lung carcinogen, can cause lung cancer; Silicosis Scaring of the lung tissue, reduced oxygen absorption. Can make one more susceptible to lung infections such as tuberculosis. Can cause Chronic Obstructive Pulmonary Disease (COPD). Can cause Kidney Disease and other Respiratory Diseases.
Chronic/Classic Silicosis 15 years to 20 years of moderate to low exposures to silica Most common type Symptoms include shortness of breath upon exercising and have clinical signs of poor oxygen/carbon dioxide exchange. In later stages, workers may experience fatigue, extreme shortness of breath, chest pain and respiratory failure Accelerated Silicosis 5 years to 10 years of high exposures to silica Symptoms include severe shortness of breath, weakness and weight loss Acute Silicosis Several months to 2 years of extremely high exposures to silica Symptoms include severe disabling shortness of breath, weakness and weight loss (often leads to death)
Flexible compliance option that effectively protects workers from silica exposure. Matches common construction tasks with dust control methods, including engineering controls, work practices and respiratory protection, in an effort to limit worker exposures to silica. If employers fully and properly implement Table 1, they are not required to measure respirable crystalline silica exposures to verify that levels are at or below the PEL for workers engaged in the Table 1 task.
If requirements of Table 1 are properly implemented for a given task, the employer will not need to conduct air monitoring or exposure assessments on their employees.
Stationary masonry saws Handheld power saws Handheld power saws for cutting cement board Walk-behind saws Drivable saws Rig-mounted core saws or drills Handheld and stand mounted drills Small drivable milling machines Crushing machines Dowel drilling rigs for concrete Vehicle-mounted drilling rigs for rock and concrete Jackhammers and handheld powered chipping tools Handheld grinders for mortar removal Handheld grinders for other uses Walk-behind milling machines and floor grinders Large drivable milling machines Heavy equipment and utility vehicles
Approximately half of tasks require an integrated water delivery system. Approximately half of tasks require shroud with dust collection system.
Table 1. Exposure Control Methods for Selected Construction Operations Operation Engineering and Work Practice Control Methods Required Air-Purifying Respirator (Minimum Assigned Protection Factor) 4 hr/day > 4 hr/day Handheld power saws (any blade diameter) Use saw equipped with integrated water delivery system that continuously feeds water to the blade. Operate and maintain tool in accordance with manufacturer s instructions to minimize dust emissions. When used outdoors. When used indoors or in an enclosed area. None APF 10 APF 10 APF 10
If a worker uses the saw outdoors for four hours or less per day, no respirator would be required. If worker uses the saw for more than four hours per day or anytime indoors, he or she would be required to use a respirator with an assigned protection factor (APF) of at least 10 (half face or dust mask).
Conduct assessments including air sampling to determine if levels are above the Action Level or PEL; Protect workers from silica exposure if above the PEL; Use dust controls to protect workers from exposure above the PEL; Provide respirators to workers when dust controls cannot limit exposures to the PEL.
Employer Obligations by Exposure Level Provision (d) Exposure assessment Exposure Level AL AL but PEL >PEL Initial assessment if employees reasonably expected to be exposed AL OR Follow Table 1 (for construction) Initial assessment if employees reasonably expected to be exposed AL Periodic monitoring every 6 months OR Performance option OR Follow Table 1 (for construction) Initial assessment if employees reasonably expected to be exposed AL Periodic monitoring every 3 months OR Performance option OR Follow Table 1 (for construction) (e) Regulated areas and access control None None Establish and implement regulated areas OR Establish and implement written access control plan
Employer Obligations by Exposure Level (cont.) Exposure Level Provision (f) Methods of compliance AL AL but PEL >PEL None None Use engineering and work practice controls where feasible OR Follow Table 1 (for construction) (g) Respiratory protection None None Provide respiratory protection to workers when exposures >PEL OR Follow Table 1 (for construction)
Employer Obligations by Exposure Level (cont.) Exposure Level Provision AL AL but PEL >PEL (h) Medical surveillance None None Provide initial exam within 30 days of assignment Provide periodic exams every three years (i) Hazard communication Provide information and training Provide information and training Provide information and training (j) Recordkeeping Maintain exposure assessment records Maintain exposure assessment records Maintain exposure assessment and medical records
When to perform air sampling for silica For tasks not listed in Table 1 Employer does not fully and properly implement the engineering controls, work practices and respiratory protection described in Table 1 Employer wants historic exposure monitoring data Reassessment of exposure required when there is a change in production, process, control equipment, personnel or work practices
Low volume air sampling pump Cyclone Calibrator Pre-weighed 37-mm PVC cassette (NIOSH 7500 Method)
Silica Sampling Cassette Configuation
Silica Web Page http://www.osha.gov/silica