Compostable mailers, if not composted directly, should be put in the trash since recycling is not an appropriate solution. This is because when placed among other recyclables like LDPE and HDPE, it will disrupt their processing at a facility due its intended single-use function. It’s important to note that even though these plastics are designed for biodegrading purposes, they often do no so effectively within landfills where oxygen levels can remain insufficiently low or moisture content too dry.