312 / | HD | SUPPORTS: CABINET STRUCTURE |
31 | WITH GAS OR VAPOR TREATMENT OF MATERIAL {3} | |
31.01 | DF | .~> By wetted surface exposed to material chamber and continuously contacted by unconfined gas {2} |
31.1 | DF | .~> Mounted on container closure |
31.2 | DF | .~> Externally accessible {1} |