Which factor is included as a cause of gasket deterioration?

• A. Ozone
• B. Paint
• C. Rust
• D. Water hardness

Answer: (A)

Ozone is a powerful oxidizer that attacks elastomeric gasket materials used in valves and fittings. It diffuses into the rubber and oxidizes the polymer chains, leading to chain scission, loss of elasticity, and cracking under stress—often called ozone cracking. This direct chemical attack weakens the gasket and can cause leaks or failure.

Paint, rust, and water hardness don’t chemically deteriorate elastomer gaskets in the same way. Paint is a surface coating and isn’t typically a primary cause of gasket aging; rust is metal corrosion, not a gasket material issue; and water hardness leads to mineral buildup rather than polymer degradation.