# SILICA:

## Protection From Overexposure for Mechanical Construction Workers

**As a mechanical construction worker, you may be exposed to respirable crystalline silica. You can protect yourself from**

### overexposure by following established safe work practices.

### Silica-related Health Concerns

**Inhaling large enough concentrations of respirable crystalline silica over a long enough period of time can result in:**

- **Silicosis**
- **Lung cancer**
- **Chronic bronchitis**
- **Kidney disease**
- **Autoimmune diseases**

### Primary Sources of Exposure in Mechanical Construction

- **Drilling holes in concrete to install pipe and duct hangers**
- **Cutting or boring through concrete ceilings, floors, or walls to run piping systems or HVAC ducts**
- **Working near other trades that are pulverizing silica-containing building materials**

### To Avoid the More Complex Alternative Exposure Control Methods

### Standard Drills, Including Impact and Rotary Hammer Drills:

- **Use a shroud or cowling and adequate dust collection system**
- **When needed, use an exhaust ventilation system to minimize visible airborne dust**
- **Clean out the drilled holes with a HEPA vacuum system**
- **Follow the tool and equipment manufacturer’s instructions to limit dust emissions**

**Rig-mounted Core Drills or Saws:**

- **Use tools equipped with an integrated water delivery system**
- **Ensure that the flow rate is strong enough to minimize visible dust**
- **Follow the tool and equipment manufacturer’s instructions to limit dust emissions**

**Saws, Including Handheld or Walk-behind Saws:**

- **Wear a respirator**
- **Use tools equipped with an integrated water delivery system**
- **Ensure that the flow rate is strong enough to minimize visible dust**
- **Follow the tool and equipment manufacturer’s instructions to limit dust emissions**

**Jackhammers and Handheld Powered Chipping Tools:**

- **Wear a respirator**
- **Use either a water delivery system with continuous spray at point of impact, and ensure that the flow rate is strong enough to minimize visible dust; or use a shroud or cowling and adequate dust collection system**
- **When working with a shroud or cowling and dust collection system, use an exhaust ventilation system when needed to minimize visible airborne dust**
- **Follow the tool and equipment manufacturer’s instructions to limit dust emissions**

**When You Have to Follow the More Complex Alternative Exposure Control Methods**

- **Wear a respirator and use engineering controls and safe work practices until your company’s exposure assessment and written silica exposure control plans are completed**
- **Follow your company’s written silica exposure control plan**

**General Safe Work Practices**

- **Use only sharp masonry drill bits and saw blades**
- **Never eat, drink, smoke, or apply cosmetics in affected work areas**
- **Wash your hands and face before eating, drinking, smoking, or applying cosmetics**
- **Avoid dry sweeping, dry brushing, and using compressed air to clean clothes or surfaces**