Gas Free Certificate : Written confirmation that a tank or other confined space has been inspected and confirmed purged of all explosive and other harmful gasses
Association of Marine Underwriters of San Francisco (AMUSF), Glossary of Marine Insurance and Shipping Terms, http://www.amusf.com/Definitions_A.htm, CA, USA 2011. (Mrtm Insur and Shipping - Amer) {575}