---
kind: "section"
citation: "46 C.F.R. § 181.405"
title: "46"
number: "181.405"
heading: "Spaces required to have fire detection systems."
url: "https://uscodex.org/cfr/46/181.405"
---

# §181.405. Spaces required to have fire detection systems.

- (a) The following spaces must be equipped with a fire detection and alarm system of an approved type installed in accordance with [46 CFR part 76](/cfr/46/part76.md), except when a fixed-gas fire extinguishing system that is capable of automatic discharge upon heat detection is installed or when the space is manned:
  - (1) **A space containing propulsion machinery.**
  - (2) **A space containing an internal combustion engine of more than 50 hp.**
  - (3) **A space containing an oil-fired boiler.**
  - (4) A space containing machinery powered by gasoline or any other fuels having a flash point of 43.3 °C (110 °F) or lower.
  - (5) A space containing a fuel tank for gasoline or any other fuel having a flash point of 43.3 °C (110 °F) or lower.
- (b) [Reserved]
- (c) Vessels described by [46 CFR 175.110(c)](/cfr/46/175.110.md?p=c) must have an interconnected fire detection system in compliance with [§ 181.450](/cfr/46/181.450.md) installed in all enclosed areas where passengers and crew have routine access, including accommodation spaces and machinery spaces.
- (d) An enclosed vehicle space must be fitted with a fire detection and alarm system of an approved type that is installed in accordance with [part 76](/cfr/46/part76.md) of this chapter.

## Notes

### Amendments

[USCG-2012-0196, 81 FR 48300, July 22, 2016; as amended by USCG-2021-0306, 86 FR 73172, Dec. 27, 2021; USCG-2024-1103, 90 FR 52881, Nov. 24, 2025]

### Authority

Authority: 46 U.S.C. 2103, 3306; E.O. 12234, 45 FR 58801, 3 CFR, 1980 Comp., p. 277; DHS Delegation 00170.1, Revision No. 01.4.

### Source

Source: CGD 85-080, 61 FR 982, Jan. 10, 1996, unless otherwise noted.

### Amendments

[USCG-2012-0196, 81 FR 48300, July 22, 2016; as amended by USCG-2021-0306, 86 FR 73172, Dec. 27, 2021; USCG-2024-1103, 90 FR 52881, Nov. 24, 2025]