Every employee going under air pressure for the first time shall be instructed on how to avoid excessive discomfort.
During the compression of employees, the pressure shall not be increased to more than 3 p.s.i.g. within the first minute. The pressure shall be held at 3 p.s.i.g. and again at 7 p.s.i.g. sufficiently long to determine if any employees are experiencing discomfort.
After the first minute the pressure shall be raised uniformly and at a rate not to exceed 10 p.s.i. per minute.
If any employee complains of discomfort, the pressure shall be held to determine if the symptoms are relieved. If, after 5 minutes the discomfort does not disappear, the lock attendant shall gradually reduce the pressure until the employee signals that the discomfort has ceased. If he does not indicate that the discomfort has disappeared, the lock attendant shall reduce the pressure to atmospheric and the employee shall be released from the lock.
No employee shall be subjected to pressure exceeding 50 pounds per square inch except in emergency.