Red Seal Gasfitter — Class A Practice Exam

What is a potential hazard of using silicone sealant on gas fittings?

1. It can evaporate quickly

2. It is flammable

3. It can off-gas acetic acid, which is corrosive to copper

4. It can cause gas leaks

The correct answer is: It can off-gas acetic acid, which is corrosive to copper

The use of silicone sealant on gas fittings poses specific hazards, one of which is the potential to off-gas acetic acid. This is a critical concern because acetic acid can be corrosive to copper and other metal components often found in gas fittings. When applied, silicone sealant often cures through a reaction that produces acetic acid as a byproduct. If this acid comes into contact with copper or other metals, it can lead to deterioration or damage over time, potentially compromising the integrity of the gas fitting. In the context of gas compliance and safety, understanding material interactions is essential. Proper materials should be selected that will not negatively impact the components they come into contact with, especially within systems carrying gases. Recognizing the corrosive potential of acetic acid allows gasfitters to make informed decisions about the materials they use in gas installations to maintain safety and functionality over time.