Any opening through a wall, the ceiling or the roof has to carry a filter or screen at the facility boundary so that animals, invertebrates included, can neither enter nor leave. The filter or screen material must be mechanically strong enough to bear any airflow load, survive regular cleaning without damage, and resist corrosion and animals getting through it. The accompanying note says that where GMOs that could be disseminated are present, those filters or screens must also be of a type and size that stops invertebrates crossing the facility boundary.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.