๐ซ Silica Exposure Prevention
Topic: Protecting yourself from crystalline silica dust Duration: 5-7 minutes Required: OSHA Silica Standard (29 CFR 1926.1153)
What is Crystalline Silica?โ
Silica is found in:
- Concrete and mortar
- Brick and block
- Stone (granite, sandstone)
- Sand
- Asphalt
- Drywall compound
When these materials are cut, drilled, ground, or crushed, silica dust is released.
Health Effectsโ
Breathing silica dust causes:
Silicosisโ
- Irreversible lung scarring
- Progressive, no cure
- Can develop even after exposure stops
Lung Cancerโ
- Silica is a known carcinogen
Other Conditionsโ
- COPD
- Kidney disease
- Autoimmune disorders
There is no safe level of silica exposure. Any exposure causes some damage.
High-Risk Tasksโ
| Task | Risk Level |
|---|---|
| Cutting concrete/masonry | Very High |
| Grinding concrete | Very High |
| Core drilling | High |
| Tuckpointing | Very High |
| Sand blasting | Extreme |
| Jackhammering | High |
| Mixing/pouring concrete | Moderate |
| Sweeping concrete dust | High |
OSHA Silica Requirementsโ
Table 1 Tasksโ
OSHA provides "Table 1" with specified controls. If you follow Table 1 exactly, you're compliant without air monitoring.
Examples from Table 1:
| Task | Required Controls |
|---|---|
| Handheld power saw | Continuous water + respiratory protection |
| Walk-behind saw | Continuous water |
| Handheld grinder | Vacuum + dust shroud + respiratory protection |
| Jackhammer | Continuous water + respiratory protection |
Exposure Limitsโ
- PEL (Permissible Exposure Limit): 50 ยตg/mยณ (8-hour TWA)
- Action Level: 25 ยตg/mยณ
Controls: The Hierarchyโ
1. Elimination/Substitutionโ
- Use materials with lower silica content when possible
2. Engineering Controlsโ
- Wet methods: Water suppresses dust at the source
- Vacuum/dust collection: Capture dust before it spreads
- Enclosed cabs: Filtered air in heavy equipment
3. Administrative Controlsโ
- Limit time in dusty areas
- Rotate workers
- Schedule dusty work when fewer people present
4. Respiratory Protectionโ
- Required when engineering controls aren't enough
- Minimum N95 for most tasks
- Some tasks require higher protection (half-mask APR, PAPR)
Respiratory Protectionโ
| Protection Level | When to Use |
|---|---|
| N95 filtering facepiece | Low exposure, short duration |
| Half-mask APR (P100) | Most Table 1 tasks |
| Full-face APR (P100) | High dust + eye protection needed |
| PAPR | Extended work, higher protection |
Fit testing required for tight-fitting respirators. Medical clearance required before respirator use.
Good Practicesโ
Do:โ
- Use wet cutting whenever possible
- Use vacuums with HEPA filters
- Clean up with wet methods or HEPA vacuum
- Wear proper respiratory protection
- Remove contaminated clothing before leaving site
Don't:โ
- Dry sweep silica dust
- Use compressed air to clean dusty clothes
- Eat, drink, or smoke in dusty areas
- Take contaminated clothes home
Signs You're Being Exposedโ
- Visible dust cloud during work
- Dust coating surfaces nearby
- Dust on clothes at end of day
- Coughing during or after work
If you see dust, you're breathing it.
Discussion Questionsโ
- What silica-generating tasks are we doing today?
- Are we using wet methods or vacuum systems?
- Does everyone have proper respiratory protection?
- Have you been fit-tested for your respirator?
Today's Commitmentโ
"I will use dust controls, wear proper respiratory protection, and never dry sweep silica dust."
Sign-Inโ
| Name | Signature | Company |
|---|---|---|
Presenter: _________________ Date: _________