1910.426(c): Mixed-Gas Diving Procedures
In mixed-gas diving, a separate dive team member must tend each diver, a standby diver must be available, and a diver must be stationed at the entry point in enclosed or confining spaces. Each operation needs primary and dive-location reserve breathing gas, with extra hose, inwater stage, bell tending and diver-carried reserve gas as the rule describes.
Key takeaways
- 1910.426(c) is part of OSHA's general industry standards (29 CFR Part 1910, Subpart T).
- OSHA cited it 2 times in the last 3 years, in 1 inspections, with $4,256 in current penalties.
- 1 death is linked to inspections that cited this rule.
- Related part: 1910.426(c)(1) (1 citations).
- Free 5-minute toolbox talk for your crew below.
In this article
What this rule covers
29 CFR 1910.426(c) ("Procedures") is one requirement inside 1910.426 Mixed-gas diving, an OSHA general industry standard (Part 1910, Subpart T). It includes 13 sub-paragraphs. The official text below is copied word for word from the Electronic Code of Federal Regulations (eCFR). The numbers, injury cases and training on this page show how OSHA enforces it on real job sites.
Official text
(c) Procedures. 2 citations
(1) A separate dive team member shall tend each diver in the water. Open (c)(1) 1 citations
(2) A standby diver shall be available while a diver is in the water. Open (c)(2) 1 citations
(3) A diver shall be stationed at the underwater point of entry when diving is conducted in enclosed or physically confining spaces.
(4) Each diving operation shall have a primary breathing gas supply sufficient to support divers for the duration of the planned dive including decompression.
(5) Each diving operation shall have a dive-location reserve breathing gas supply.
(6) When heavy gear is worn:
(i) An extra breathing gas hose capable of supplying breathing gas to the diver in the water shall be available to the standby diver; and
(ii) An inwater stage shall be provided to divers in the water.
(7) An inwater stage shall be provided for divers without access to a bell for dives deeper than 100 fsw or outside the no-decompression limits.
(8) When a closed bell is used, one dive team member in the bell shall be available and tend the diver in the water.
(9) Except when heavy gear is worn or where physical space does not permit, a diver-carried reserve breathing gas supply shall be provided for each diver:
(i) Diving deeper than 100 fsw or outside the no-decompression limits; or
(ii) Prevented by the configuration of the dive area from directly ascending to the surface.
Source: eCFR, text current as of 2026-10-15. Read all of 1910.426.
Injuries linked to this rule
1 death is linked to inspections where OSHA cited 1910.426(c).
At 3:18 p.m. on October 2, 2024, Employee #1, employed as a shellfish fishing diver near Sisters Island, was diving for Geoducks in an area experiencing strong tides and rough seas. After starting his second dive of the day, Employee#1 radioed the tender aboard the…
Where and how often it was cited
Free toolbox talk
A 5-minute crew talk on 1910.426(c), plus alerts when this rule changes. Free.
OSHA interpretation letters
None exist. OSHA has not published a letter of interpretation for 1910.426(c).
Related parts of this rule
- 1910.426(c)(1) 1 citations
- 1910.426(c)(2) 1 citations
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Frequently asked questions
Must a standby diver be available?
Yes. A standby diver shall be available while a diver is in the water.
When is an inwater stage needed?
When heavy gear is worn, and for divers without access to a bell on dives deeper than 100 fsw or outside the no-decompression limits.
What is required when a closed bell is used?
One dive team member in the bell shall be available and tend the diver in the water.
About this page
Sources
- 29 CFR 1910.426 (eCFR), text current as of 2026-10-15
- U.S. Department of Labor enforcement data: OSHA inspections, citations and accident records, copied nightly; data as of 2026-10-20
3-year window. Federal OSHA only; state-plan rules are not counted. Plain-language text is a summary, not legal advice; the official text controls. Black Belt Safety is not part of OSHA or the Department of Labor.