Asbestos Cement: Composition, Historical Use, and Health Hazards

Asbestos cement (transite) is a composite material: Portland cement reinforced with 10–15% asbestos fibers (chrysotile, crocidolite, amosite). Widely used 1920s–1980s for:

• Roofing/siding shingles and sheets
• Water/sewer pipes
• Wallboard, soffits, fascia
• Flue pipes, electrical conduits

Health Risks

Intact, undisturbed asbestos cement poses minimal risk. Danger arises when fibers are released by cutting, drilling, sanding, breaking, pressure washing, or deterioration.

• Asbestosis: Pulmonary fibrosis from chronic exposure.
• Lung cancer: Risk multiplied by smoking.
• Mesothelioma: Pleural/peritoneal malignancy; latency 20–50 years.
• Pleural plaques/thickening: Benign but indicate exposure.

Regulatory Status

• Banned in 60+ countries (EU, Australia, Japan, Canada).
• U.S.: Partial bans (spray-on, pipe insulation); cement products not fully banned but heavily regulated (NESHAP, OSHA, AHERA).

Management

• Identify via licensed inspector.
• Leave intact if undamaged; encapsulate/seal.
• Removal only by licensed abatement contractors with containment, negative air, PPE.
• Dispose as regulated asbestos waste.

Never dry-sweep, sand, or power-wash suspected asbestos cement.