and instructions shall be deemed confidential, and the Bureau will appropriately safeguard them against disclosure,
(i) Breathing apparatus will be tested for manufacturers or accredited agents of manufacturers and for inventors.
(ii) The Bureau of Mines will make public from time to time a list of permissible self-contained breathing apparatus and data on tests of such equipment.
§ 11.3 Fees for testing.
| Apparatus with separate regenerator | Oxygen generating apparatus | Demand-type apparatus | |
| Complete 2-hour self-contained breathing apparatus inspection and tests | $1500 | $1500 | $1500 |
| Complete 1-hour self-contained breathing apparatus inspection and tests | 1390 | 1390 | 1390 |
| Complete ¾-hour self-contained breathing apparatus inspection and tests | 1390 | 1390 | 1390 |
| Complete ½-hour self-contained breathing apparatus inspection and tests | 1390 | 1390 | 1390 |
| Separate preliminary 2-hour apparatus inspection and tests | 230 | 230 | 230 |
| Separate preliminary 1-hour apparatus inspection and tests | 230 | 230 | 230 |
| Separate preliminary ¾-hour apparatus inspection and tests | 230 | 230 | 230 |
| Separate preliminary ½-hour apparatus inspection and tests | 230 | 230 | 230 |
Fees for testing unusually complicated types of self-contained breathing apparatus and for extensions of approval will be based on the actual cost of testing, as determined by the Bureau of Mines in advance: the applicant will be notified and the fees paid before the tests are begun.
§ 11.4 General requirements. To receive approval of the Buresiu of Mines for any type of self-contained breathing apparatus deseribed under types A, B, C, or D in the following, the apparatus must comply with the requirements specified. Four general types of self-contained breathing apparatus will be tested—type A, ½-hour; type B, ¾-hour; type C, l-hour; and type D, 2-hour. To be approved each type of breathing apparatus must pass satisfactorily all of the tests specified for the respective type in § 11.7. The Bureau considers that the A, ½-hour, and B, ¾-hour, types are suitable for mine rescue and recovery work as auxiliary equipment only.
(a) The amount of oxygen or air supplied by the apparatus must meet the needs of the wearer at all times.
(b) The apparatus shall be free from mechanical obstructions so that the wearer can breathe freely at all times.
(c) The temperature of the inspired atmosphere shall not exceed 110° F. when the temperature of the atmosphere external to the apparatus does not exceed 85° F. The Bureau will not test self-contained breathing apparatus when the temperature external to the exceeds 85° F. or is less than 60° F.
(a) The apparatus shall be durable in construction, and all vital parts shall be so protected as to prevent damage or excessive wear during the tests to which it will be subjected,
(e) (1) For an apparatus, equipped with a mouth-breathing device in which the expired atmosphere is recirculated and which utillizes a supply of compressed oxygen and a regenerator, the regenerating material (absorbent) shall absorb carbon dioxide from the expired atmosphere. Samples of the atmosphere within the apparatus shall be taken for analytical determination of carbon dioxide content, The atmosphere within the apparatus shall be sampled as near to the point of inspiration as practicable, only while the wearer is inhaling, over & period covering several inhalations, and at uniform intervals of time. None of the samples so taken shall contain more than 2% percent of carbon dioxide. The average carbon dioxide content of all atmospheric samples taken from within the apparatus during the test shall not exceed 1 percent.
