in atmospheric chemistry
Hydrocarbons purged during refinery shutdowns and startups which should be piped to storage systems for safe venting, flaring or recovery. This term also applies to the purging of water in boiler operation, and serves in the control of dissolved solids in the boiler water.
PAC, 1990, 62, 2167 (Glossary of atmospheric chemistry terms (Recommendations 1990)) on page 2176