Section 428. Physical examinations

If an employee is a new employee, an
  absentee for ten or more successive days, an employee who has worked  in
  compressed air continuously for three months or a beginner in compressed
  air  who  has  worked  but  a  single  shift as required by section four
  hundred and thirty, the officer or officers required by subdivision  one
  of  section  four hundred and twenty-seven shall examine him and declare
  him physically fit to work in compressed air before  permitting  him  to
  enter or re-enter the working chamber.