Silica Training
Silica Intro Silica is the second most common element on earth It is 28% of the earth s crust Several forms Crystalline Amorphous (non crystaline) Types: Quartz Cristobalite Tridymite Found: dirt, rocks, drywall
Oregon OSHA You have the right to a safe and healthy workplace Employees have the right to report workrelated injuries and illnesses free from retaliation
Oregon OSHA Silica Rule 437-002-1057 through 1065 Excludes: Agriculture Sorptive clays (kitty litter) Operations where data shows exposure less than 25 µg/m 3 (8-hour TWA) (examples: removing formwork, pouring concrete for post holes) Includes: Construction activities General Industry
Health Hazards/ Diseases Silicosis Lung cancer Tuberculosis (TB) Other respiratory diseases Non-malignant respiratory diseases (chronic obstructive pulmonary disease, emphysema) Cancer (increased risk to other cancers; larynx, stomach, esophageal) Kidney and immune diseases
Disease Pattern Crystalline silica is broken and released into the air by grinding, crushing, drilling, etc. Particles smaller than 5 µm enter lower respiratory pathway Lungs react and form fibrotic nodules, which scars lungs The nodules and scarring can form into silicosis a progressive disease that is irreversible and fatal
Symptoms Initially: No symptoms Progression: Difficulty breathing, coughing, sweating, fever, weakness Advanced: Continued difficulty breathing, airflow obstruction
Chronic (>10 years) Accelerated (5 to 10 years) Acute (<5 years) Types of Silicosis
Oregon OSHA Exposure Limits Action Limit: (AL) 25 µg/m 3 Same as American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Values (TLV) Permissible Exposure Limit: (PEL) 50 µg/m 3
Two methods of compliance Specified Exposure Control Methods: Must fully implement according to Table I Do not have to assess airborne silica No visible dust, eliminate or minimize Alternative Control Methods: Determine airborne silica exposures Limit exposures below PEL Use engineering, administrative controls Use PPE Keep records of exposure
All employers must: Provide respiratory protection (when required) Restrict housekeeping practices that can cause exposure Establish a written control plan and competent person Offer medical exams to employees who wear a respirator 30 days or more per year Communicate hazards (training) Keep records of medical exams
Silica Producing Tasks All occupational exposures to crystalline silica (except those below 25 µg/m 3 ) including: Chipping, hammering, and drilling Crushing, loading, hauling, and dumping Abrasive blasting, or using an abrasive containing silica or sand Sawing, hammering, drilling, grinding, or chipping Dry sweeping or pressurized air blowing of concrete, rock, or sand dust
Silica Producing Equipment Stationary masonry saws Handheld power saws Walk behind and drivable saws Rig mounted core saws and drills Handheld and mounted drills Dowell drilling rigs (and vehicle mounted) Jackhammers and power chipping tools Grinders (hand and floor) Milling machines Crushing machines Heavy equipment or any equipment
Specified Controls: Table I
Specified Controls: Table I Everyone who is engaged in task must comply Must be fully implemented Manufacturers instructions Correct respiratory protection (minimum assigned protection factor) No visible dust Refer to (Federal) OSHA s Small Entity Guide for details on specific Tasks from Table I
Alternative Exposure Control Methods (not Table I) Methods to assess employee exposures to crystalline silica using alternative controls Must control below the PEL (50 µg/m 3 ) Provide information to employees about their exposure levels Giving information to the health care person performing medical evaluations
Alternative Control Methods two types Performance Option Use air monitoring or objective data to determine employee exposures For example: Industry surveys Calculations Area sampling and mapping Scheduled Monitoring Eight-hour time weighted average (TWA) Characterize each employee s exposure One full shift monitoring for each job classification <Action Limit no further monitoring Between AL and PEL six months >PEL every three months
Alternative Controls Scheduled Monitoring Many other elements including: Reassessment of exposures Verification of sample analysis Employee notification within five days Observation of monitoring Consideration of other methods of compliance
Prevention Hierarchy of Controls Elimination Engineering Controls Administrative Controls Personal Protective Equipment
Eliminate Use a substitute (non-crystalline silica containing products) Usually not an option
Engineering Controls Control Keep silica from becoming airborne Wet methods Local exhaust Dust controls Isolation of activity (enclosed cab of equipment) Eliminate the source/hazard Ex: Masons cutting block, dry sweep
Newport Aquarium
NIOSH Drywall Sanding Solution
Concrete Ready-Mix Drum
Dixie Cup and Shaving Cream
Local Exhaust
Silica-safe.org
NIOSH Jackhammers, cut-off saws, tuckpointing, concrete grinders
NIOSH DIY Jackhammer
OSHA Controlling Silica in Construction
Administrative Controls Other trades Control other work in the area Pre-plan
Personal Protective Equipment Protective clothing Respirators (used as a last resort) Tight fitting Cartridge filters (N100, P100, R100) Powered Air Purifying Respirator (PAPR)
Housekeeping* No dry sweeping of dust Unless the use of HEPA vacuums or wet methods are not feasible No cleaning with compressed air *when housekeeping could contribute to employee exposure to respirable crystalline silica
Exposure Control Plan Must be in place for anyone covered in the standard and must be available to all Must include: Tasks Controls Housekeeping Procedures to restrict access Competent person CPWR www.silica-safe.org
Competent Person Can identify hazards to crystalline silica Authorized to control, eliminate, or minimize the hazard Has knowledge and ability to implement written Exposure Control Plan Training as described in: 437-002-1059(2), 437-002-1058(2)(b), and 437-002-1063(2)
Medical Surveillance Anyone who wears a respirator for more than 30 days/year Be performed every three years (or sooner, if recommended) Must provide work history Exam focuses on respiratory system and spirometry test
Communication of Hazard Employers must train and inform employees of the hazards of respirable crystalline silica Must discuss: Health hazards Specific tasks Specific control methods OSHA silica standard Competent person Purpose and description of medical surveillance
Recordkeeping Keep for 30 years Air monitoring data Objective data Medical surveillance (employment + 30 years)
Crystalline Silica This material has been made possible by a grant from the Oregon Occupational Safety and Health Division, Department of Consumer and Business Services
Post Test (True / False) 1. Silica is a mineral, and basically harmless. 2. Silica overexposure can cause silicosis. 3. OSHA was created to protect workers rights. 4. Concrete and dirt do NOT have silica in them. 5. Using compressed air is the best method to clean up dirt and dust.