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)

• Found: dirt, rocks, drywall

• Types:

– Quartz

– Cristobalite

– Tridymite

Oregon OSHA

• You have the right to a safe and healthy workplace

• Employees have the right to report work-related 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/m3 (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

Types of Silicosis

• Chronic

(>10 years)

• Accelerated

(5 to 10 years)

• Acute

(<5 years)

Oregon OSHA Exposure Limits

Action Limit:

(AL)

• 25 µg/m3

• Same as American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Values (TLV)

Permissible Exposure Limit:

(PEL)

50 µg/m3

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/m3) 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/m3)

• 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

Control

• Engineering Controls

– 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.