The material of the OFMSW (organic fraction of municipal solid waste) collection bags also has a value for biogas production. There are three main materials used: paper, plastic and biodegradable. The first, in order to hold the weight of the waste, must be thick but this does not facilitate its disposal, while the other two are much thinner and it has been shown that biodegradable bags lead citizens to pay more attention to correctly separating organic waste from generic waste.