The AS2628 was developed to form a common definition of a gas-tight, sealable silo which is suitable for fumigation. For a silo to meet the AS2628 it must perform a five minute, half-life pressure test. If a silo meets this pressure test, it will hold phosphine gas and other fumigants at a concentration high enough and for long enough to kill insects at all life stages (eggs, larvae, pupae). For more information see ‘Pressure testing sealable silos