Lower explosive limit
(5) Lower explosive limit means the lowest percent by volume of a mixture of explosive gases which will propagate a flame in air at 25 C and atmospheric pressure. (6) Periodic application of cover material means the application and compaction of soil or other suitable material over disposed solid waste at the end of each operating day or at such frequencies and in such a manner as to reduce the risk of fire and to impede disease vectors' access to the waste. (7) Putrescible wastes means solid waste which contains organic matter capable of being decomposed by microorganisms and of such a character and proportion as to be capable of attracting or providing food for birds.