Fumigation with gas recirculation method is often applied when fumigating with Aluminium Phosphide. Reason: Aluminium Phosphide reacting with moisture will release Phosphine with relatively light weight (with density at 1.17 compared to the air) which hardly disperses deeply into goods in the bottom of hold, especially for consignments with big volume. To ensure the dispersion of chemical concentration at all places in hold as well as improve fumigation results, many customers require gas recirculation method - J System. Currently, VFC is the only company in Vietnam applying such fumigation method under license. The working principle of this system is fully presented in part Technical information - J System – Advanced fumigation method.