1. Hydrocarbons and Hydrogen

Methane (CH4)

Ethane (C2H6)

Ethylene (C2H4)

Acetylene (C2H2)

Hydrogen (H2)

2. Carbon Oxides

Carbon monoxide (CO)

Carbon dioxide (CO2)

3. Atmospheric Gases (non-fault gases)

Nitrogen (N2)

Oxygen (O2)