Source: https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=FEDERAL_REGISTER&p_id=18073
Timestamp: 2015-05-28 06:14:34
Document Index: 70299674

Matched Legal Cases: ['art 1910', '§ 1910', '§ 1910', '§ 1910', '§ 1910', '§ 1910', '§ 1910', '§ 1910', '§ 1910', '§ 1910']

Commercial Diving Operations - 69:7351-7366
69:7351-7366
1910; 1910.401; 1910.402; 1910.424; 1910.430
DEPARTMENT OF LABOR Occupational Safety and Health Administration 29 CFR Part 1910 [Docket No. S-550] RIN 1218-AB97 Commercial Diving Operations AGENCY: Occupational Safety and Health Administration (OSHA), Department of Labor. ACTION: Final rule.
SUMMARY: OSHA is issuing this final rule to amend its Commercial Diving Operations (CDO) standards. This final rule allows employers of recreational diving instructors and diving guides to comply with an alternative set of requirements instead of the decompression-chamber requirements in the current CDO standards. The final rule applies only when these employees engage in recreational diving instruction and diving-guide duties; use an open-circuit, a semi-closed-circuit, or a closed-circuit self-contained underwater-breathing apparatus supplied with a breathing gas that has a high percentage of oxygen mixed with nitrogen; dive to a maximum depth of 130 feet of sea water; and remain within the no-decompression limits specified for the partial pressure of nitrogen in the breathing-gas mixture. These alternate requirements essentially are the same as the terms of a variance granted by OSHA to Dixie Divers, Inc. in 1999. DATES: This final rule becomes effective on March 18, 2004. ADDRESSES: In compliance with 28 U.S.C. 2112(a), OSHA designates the Associate Solicitor of Labor for Occupational Safety and Health as the recipient of petitions for review of this final rule. Submit petitions of review to the Associate Solicitor at: Office of the Solicitor of Labor, Room S-4004, U.S. Department of Labor, 200 Constitution Avenue, NW., Washington, DC 20210. FOR FURTHER INFORMATION CONTACT: For general information and press inquiries, contact Mr. George Shaw, Office of Communications, Room N-3647, OSHA, U.S. Department of Labor, 200 Constitution Avenue, NW., Washington, DC 20210; telephone (202) 693-1999. For technical inquiries, contact Mr. Robert Bell, Directorate of Standards and Guidance, Room N-3609, OSHA, U.S. Department of Labor, 200 Constitution Avenue, NW., Washington, DC 20210; telephone (202) 693-2053 or fax (202) 693-1663.
Copies of this Federal Register notice are available from the OSHA Office of Publications, Room N-3101, U.S. Department of Labor, 200 Constitution Avenue, NW., Washington DC 20210; telephone (202) 693-1888. For an electronic copy of this notice, go to OSHA's Web site (http://www.osha.gov), and select "Federal Register," "Date of Publication," and then "2003." SUPPLEMENTARY INFORMATION: Table of Contents The following Table of Contents identifies the major sections under Supplementary Information, including a detailed summary and explanation of the final rule. I. Background
A. Final §§ 1910.401(a)(3) and 1910.402 ("Definitions")
B. Conditions Specified in Final Appendix C
IV. Final Economic Analysis and Regulatory Flexibility Certification
VII. State Plans
IX. Applicability of Existing Consensus Standards
X. Authority and Signature
I. Background In 1999, acting under section 6(d) of the Occupational Safety and Health Act of 1970 ("OSH Act" 29 U.S.C. 655), the Occupational Safety and Health Administration ("OSHA" or "the Agency") published an order granting a permanent variance to Dixie Divers, Inc. ("Dixie Divers") (Ex. 2-11). The permanent variance exempted Dixie Divers from OSHA's decompression-chamber requirements specified at § 1910.423(b)(2) and (c)(3)(iii), and § 1910.426(b)(1), when its recreational diving instructors and diving guides (hereafter, "divers") engage in underwater instructional and guiding operations.
The purpose of having a decompression chamber available and ready for use at a dive site is to treat decompression sickness (DCS) and arterial gas embolism (AGE). DCS may occur from breathing air or mixed gases at diving depths and durations that require decompression, while AGE may result from over-pressurizing the lungs, usually following a rapid ascent to the surface during a dive without proper exhalation.
The Dixie Diver variance from the decompression-chamber requirements applied only to mixed-gas diving operations at a maximum depth of 130 feet of sea water ("fsw") performed within no-decompression limits. During these diving operations, divers use a breathing-gas mixture consisting of a high percentage of O2 mixed with nitrogen (i.e., a nitrox breathing-gas mixture) supplied by an open-circuit, semi-closed-circuit or closed-circuit self-contained underwater breathing apparatus (SCUBA). In issuing the permanent variance, the Agency noted that compliance would provide divers with a level of protection that met or exceeded the level of protection they would receive if they had access to a decompression chamber at the dive site as required by §§ 1910.423(b)(2) and (c)(3)(iii), and 1910.426(b)(1).
On January 10, 2003, OSHA proposed to amend its Commercial Diving Operations ("CDO") standards to incorporate the terms and conditions of the Dixie Divers variance as an appendix to the CDO standards (68 FR 1399). The Agency now is issuing the final rule to amend the CDO standards based on this proposal. OSHA believes that this amendment enables recreational diving instructors and diving guides to extend their diving operations while minimizing their risk of DCS and AGE. The Agency concludes that the recreational diving instructors and diving guides covered by this amendment will receive a level of safety and health protection that is equivalent to recreational diving instructors and diving guides who have a decompression chamber located at the dive site during mixed-gas diving operations regulated under the CDO standards. Therefore, a decompression chamber near the dive site is unnecessary for the divers covered by this final rule. II. Summary and Explanation of the Final Rule OSHA received no requests for a hearing on the proposed amendment, thereby enabling it to proceed directly to this final rule after considering the comments submitted by the public in response to the proposal. In this regard, the Agency received 13 public comments on the proposal. However, two commenters each submitted a duplicate set of responses (Exs. 6-6 and 6-7, and 6-8 and 6-9); one set of duplicate responses (Exs. 6-6 and 6-7) was received from a commercial diver that involved an issue unrelated to this rulemaking. We address the remaining comments in sections A and B below, which discuss the conditions adopted in the final rule.
When the discussion regarding a condition does not cite a comment, then the public did not comment on that condition. In such cases, we have assumed that the regulated community found the proposed condition to be appropriate and necessary for diver safety based on OSHA's stated rationale in the proposed rule, and we have retained it in the final rule without further explanation (see 68 FR 1399, pages 1400-1409). A. Final §§ 1910.401(a)(3) and 1910.402 ("Definitions") Proposed § 1910.401(a)(3) specified that this amendment would apply only to recreational diving instructors and diving guides who are engaged solely in recreational diving instruction and dive-guiding operations. Accordingly, OSHA also proposed to add the following definitions for "recreational diving instruction" and "dive-guiding operations" to § 1910.402 of the CDO standards: "Recreational diving instruction" means the training of diving students in the use of recreational diving procedures and the safe operation of diving equipment, including open-circuit, semi-closed-circuit, or closed-circuit SCUBA during dives.
"Dive-guiding operations" means the leading of groups of trained sports divers, who use open-circuit, semi-closed-circuit, or closed-circuit SCUBA, to local undersea diving locations for recreational purposes. To further limit application of the amendment, proposed § 1910.401(a)(3) required employers to ensure that the instructors and guides conduct these dives within the no-decompression limits, and that they use a nitrox breathing-gas mixture consisting of a high percentage of O2 (more than 22% by volume) mixed with nitrogen and supplied by an open-circuit, semi-closed-circuit, or closed-circuit SCUBA. Under this proposed requirement, employers also would have to comply with the requirements specified in new Appendix C of subpart T.
Based on its analysis of the record, OSHA is adopting proposed §§ 1910.401(a)(3) and 1910.402 in the final rule. Recreational diving instructors and diving guides who use a nitrox breathing-gas mixture supplied by an open-circuit, semi-closed-circuit, or closed-circuit SCUBA under no-decompression diving limits will receive a level of safety and health protection equivalent to the recreational diving instructors and diving guides who have a decompression chamber located at the dive site during mixed-gas diving operations regulated under the CDO standards. B. Conditions Specified in Final Appendix C OSHA proposed to add a new appendix to the CDO standards to specify the conditions under which employers may use this alternative to decompression chambers. Accordingly, the Agency is adopting new Appendix C in the final rule after revising the proposal based on comments submitted to the record. The following discussion addresses the comments received on the proposed conditions, and what OSHA is including in the final rule.
1. Equipment Requirements for Rebreathers
(a) Manufacturer's instructions. As proposed, this condition required employers to ensure that their recreational diving instructors and diving guides use rebreathers (i.e., semi-closed circuit and closed-circuit SCUBA) according to the rebreather manufacturer's instructions. OSHA is retaining this condition in the final rule. As noted in the proposal, the Agency believes that SCUBA manufacturers are best qualified to identify and specify the components, configuration, and operation of their products.
(b) Counterlungs. This proposed condition required employers to ensure that each rebreather has a counterlung (also referred to as an "inhalation bag" or "breathing bag") that both contains a baffle system that prevents moisture from entering the scrubber or breathing hoses and supplies a sufficient volume of breathing gas to the divers to sustain their respiration rate during diving operations. The National Oceanic and Atmospheric Administration (NOAA) considers counterlungs a necessity for rebreather diving (see Ex. 3-12, p. 14-3). OSHA expects rebreather manufacturers to provide the purchaser or user with information regarding this displacement as part of their usual and customary practice. In addition, by keeping moisture from entering the scrubber, baffle systems prevent rapid deterioration of the CO2-sorbent material housed in the scrubber and decrease the risk of CO2 toxicity (see Ex. 3-12, p. 14-8).
The Agency received one comment (Ex. 5-2-1) regarding the proposed baffle-system requirement. This commenter recommended revising the condition to read that the counterlung must contain "a baffle system and/or other moisture separating system that keeps moisture from entering the scrubber." In justifying this revision, the commenter stated: "While all manufactured units have some sort of system to accomplish this function, all do not call it a "baffle" system. Additionally, use of the specific term may * * * create problems for future technological developments, which may address the problem in different ways." OSHA agrees with this commenter that the proposed wording was too specific, and might hinder future efforts to develop new technologies to prevent moisture from entering the scrubber. Therefore, the final rule adopts the language of the proposed condition except for the part addressing baffle systems; for this part, the Agency is adopting the language recommended by this commenter.
(c) Moisture traps. Under this proposed condition, employers need to place a moisture trap in the breathing loop of each rebreather. The employer also must ensure that the rebreather manufacturer approves both the moisture trap and its location in the breathing loop, and that their divers use the moisture trap according to the rebreather manufacturer's instructions. The Agency is retaining this condition in the final rule as proposed because it believes that moisture traps, when approved by the rebreather manufacturer and located and used according to the manufacturer's instructions, prevent water from entering the CO2-absorbing canisters. By preventing such water leakage, moisture traps preserve the CO2-absorbing properties of the sorbent material inside the canister.
(d) Moisture sensors. Under this proposed condition, employers must ensure that each rebreather has a continuously functioning moisture sensor that connects to a visual (e.g., digital, graphic, or analog) or auditory (e.g., voice, pure tone) alarm. This alarm must be readily detectable by divers under the diving conditions in which they operate and warn them of moisture in the breathing loop in sufficient time for them to terminate the dive and return safely to the surface. Additionally, the proposed condition required employers to ensure that their divers use the moisture sensors according to the rebreather manufacturer's instructions. By warning divers of hazardous water leakage into the canister, moisture sensors allow divers to return to the surface before CO2 in the recycled breathing gas reaches dangerous levels. Therefore, the final rule includes these requirements as proposed.
(e) CO2 sensors. An important component in controlling excessive CO2 is the CO2 sensor. In the proposal, this condition required employers to ensure that each rebreather contains a continuously functioning CO2 sensor in the breathing loop. It also specified that the rebreather manufacturer must approve the CO2 sensor and its location in the breathing loop. In addition, employers must ensure that the CO2 sensor is integrated with an alarm that operates in a visual (e.g., digital, graphic, or analog) or auditory (e.g., voice, pure tone) mode readily detectable by divers under the diving conditions in which they operate. This alarm would remain continuously activated when the inhaled CO2 level reaches and exceeds 0.005 atmospheres absolute ("ATA").(1) In the final rule, OSHA is retaining the condition as proposed.
(f) Calibrating CO2 sensors. This proposed condition stated that employers must, before each day's diving operations (and more often when necessary), calibrate each CO2 sensor according to the sensor manufacturer's instructions. Additionally, employers must maintain the accuracy of the equipment and procedures used to perform the calibration to within 10% of a CO2 concentration of 0.005 ATA or less according to the sensor manufacturer's instructions. Using this equipment, they would calibrate the CO2 sensor to within 10% of a CO2 concentration of 0.005 ATA or less. The Agency is including this condition in the final rule because it concludes that this calibration requirement is necessary to identify improperly functioning CO2 sensors.
(g) Faulty CO2 sensors. In the proposal, this condition specified that employers must replace CO2 sensors that fail the accuracy requirements delineated above in Condition 1(f)(iii) with a sensor that meets these requirements. Eliminating sensors that are unreliable or that cannot function under rugged diving conditions is necessary to provide divers with safe breathing gas. OSHA is retaining this requirement in the final rule.
(h) CO2-sorbent materials. As an alternative to using continuously functioning CO2 sensors, the proposed condition allowed an employer to implement a rebreather manufacturer's schedule for replacing the CO2-sorbent material in the canister of a rebreather. However, the manufacturer would have to develop the schedule according to the canister-testing protocol specified in Condition 11 of Appendix C ("Testing Protocol for Determining the CO2 Limits of Rebreather Canisters"). Additionally, the employer may use the rebreather at a water temperature that is lower than the minimum, or higher than the maximum, water temperature used in the testing protocol specified in Condition 11, but only when the rebreather manufacturer adds that lower or higher temperature to the testing protocol.
A commenter (Ex. 5-2-1) stated that the proposed language regarding the minimum and maximum water-temperature requirement was confusing, and recommended that the requirement read as follows: "A rebreather within the temperature range for which the manufacturer conducted its scrubber canister tests following the protocol specified in Condition 11. Variations above or below the range are acceptable only after the manufacturer adds that lower or higher temperature to the protocol." OSHA agrees that the commenter's revision expresses more clearly than the proposal the meaning of this provision, and has revised this language in the final rule accordingly. The Agency believes that the canister-replacement schedule provides a reliable estimate of canister duration that incorporates an assessment of the physical properties of the CO2-sorbent material and an evaluation of the canister's effectiveness.
(i) Commercially pre-packed cartridges. This proposed condition required employers who use a CO2-sorbent replacement schedule specified in Condition 1(h) to ensure that each rebreather uses a manufactured (i.e., commercially pre-packed), disposable scrubber cartridge. This cartridge would have to contain a CO2-sorbent material that is approved by the rebreather manufacturer and is capable of removing CO2 from the divers' exhaled gas. In this regard, the canister would maintain the CO2 level in the breathable gas (i.e., the gas a diver is inhaling directly from the regulator) below a partial pressure of 0.01 ATA.
OSHA is including this condition in the final rule as proposed. These requirements ensure proper compression and uniform distribution of the sorbent material in the cartridge, thereby minimizing "channeling" in the material (2) and lowering the diver's risk of rebreathing exhaled breathing gas that is high in CO2.
(j) Alternative to commercially pre-packed cartridges. This proposed condition permitted employers to fill CO2 scrubber cartridges manually instead of using commercially pre-packed cartridges. This practice is acceptable when the rebreather manufacturer designs the scrubber cartridge to be filled manually, the employer implements the alternative method according to the rebreather manufacturer's instructions, and the employer can demonstrate that the alternative method meets the performance requirements for commercially pre-packed cartridges specified by Conditions 1(h) and 1(i). OSHA is adopting this condition in the final rule as proposed because manually filled cartridges that meet the performance requirements for commercially pre-packed cartridges will remove CO2 effectively from the breathing loop.
(k) Information module. In the proposal, this condition required employers to ensure that their divers use an information module that provides them with critical information regarding rebreather operation. For all rebreathers, the module needed to contain visual or auditory warning devices that would alert the diver to electrical weaknesses or failures (e.g., solenoid failure, low battery levels). In addition, modules used in semi-closed circuit rebreathers needed to contain visual displays for the partial pressure of CO2, or deviations above and below a preset CO2 partial pressure of 0.005 ATA. For closed-circuit rebreathers, the module also would have visual displays for the partial pressures of O2 and CO2, or deviations above and below a preset CO2 partial pressure of 0.005 ATA and a preset O2 partial pressure of 1.40 ATA. The module also needed to have a visual display for both gas temperature in the breathing loop and water temperature.
OSHA is including these requirements in the final rule as proposed because warning divers of electrical weaknesses and failures informs them not to rely on their electrically operated equipment and to take protective actions. Providing information about O2 and CO2 partial pressures alerts divers to rising and potentially toxic levels of these gases in time for them to prevent extended exposure. Additionally, information regarding water temperature warns divers of the risk of hypothermia, while gas-temperature information allows divers to estimate the duration of their CO2-sorbent material.
(l) Checking electrical power and circuits. Under this proposed condition, employers would ensure that the electrical power supplies and electrical and electronic circuits in each rebreather are operating according to the rebreather manufacturer's instructions. Employers must check for proper operation prior to beginning diving operations each day, and more often when necessary. The Agency is adopting this condition as proposed because partial or total electronic failures could interfere with rebreather sensor and control systems.
2. Special Requirements for Closed-Circuit Rebreathers
(a) Supply-pressure and temperature sensors. This proposed condition stated that employers are responsible for ensuring that closed-circuit rebreathers use supply-pressure sensors for the O2 and diluent gases (i.e., air or nitrogen), as well as continuously functioning sensors for detecting temperature in the inhalation side of the breathing loop and in the ambient water. OSHA is including it in the final rule as proposed. In this regard, supply-pressure sensors inform divers of the remaining supply of breathing-gas ingredients (i.e., O2 and air or nitrogen), thereby enabling them to monitor their breathing-gas consumption during a dive. Low gas supplies alert divers to an unusually high consumption of breathing gas, indicating a possible problem with the rebreather. An unexpected gas loss also may increase the need for a diver to make a rapid (i.e., emergency) ascent to the surface during a dive, which could result in over-pressurization of the lungs associated with AGE. In addition, OSHA believes that temperature sensors increase diver safety because the sensors alert divers to the possibility of hypothermia. Temperature reductions in breathing gas also inform divers that the efficiency of the CO2-sorbent material is likely to deteriorate (Ex. 3-11).
(b) O2 sensors. As proposed, this condition required employers to ensure that at least two O2 sensors are located in the inhalation side of the breathing loop. These O2 sensors must function continuously, compensate for variations in temperature, and be approved by the rebreather manufacturer. The Agency is including the condition in the final rule as proposed because the sensors provide divers with critical information regarding O2 levels in the breathing gas. Accurate information about O2 levels enables divers to maintain appropriate amounts of O2 in the breathing gas, thereby minimizing the need for emergency escape.
(c) Calibrating O2 sensors. This proposed condition specified that employers must calibrate O2 sensors as required by the sensor manufacturer's instructions before the start of each day's diving operations and more often when necessary. In performing this requirement, employers would: (i) Ensure that the equipment and procedures used to perform the calibration are accurate to within 1% of the O2 fraction by volume; (ii) maintain the accuracy of the calibration equipment as required by the manufacturer of the equipment; (iii) ensure that the sensors are accurate to within 1% of the O2 fraction by volume; (iv) replace O2 sensors when they fail to meet the specified accuracy requirements; and (v) ensure that the replacement O2 sensors meet these accuracy requirements.
OSHA believes that the levels of accuracy specified under this condition provide an adequate safety margin for the divers to detect anomalous O2 concentrations, to identify the cause of the anomaly and adjust breathing-system controls accordingly, and to ascend to the surface when necessary. Additionally, proper and timely calibration of O2 sensors, as well as accurate information regarding the level of O2 in the breathing loop, provides divers with an opportunity to take corrective action should the O2 level exceed the specified parameters. Maintaining proper O2 levels will prevent the central nervous system and pulmonary effects of O2 toxicity, and will protect divers from death and injury. Accordingly, the Agency is including these O2-sensor requirements in the final rule as proposed.
(d) Controlling O2 delivery.