46 CFR § 181.405 - Spaces required to have fire detection systems.

---
identifier: "/us/cfr/t46/s181.405"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "46 CFR § 181.405 - Spaces required to have fire detection systems."
title_number: 46
title_name: "Shipping"
section_number: "181.405"
section_name: "Spaces required to have fire detection systems."
chapter_name: "COAST GUARD, DEPARTMENT OF HOMELAND SECURITY"
subchapter_number: "T"
subchapter_name: "SMALL PASSENGER VESSELS (UNDER 100 GROSS TONS)"
part_number: "181"
part_name: "FIRE PROTECTION EQUIPMENT"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
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."
regulatory_source: "CGD 85-080, 61 FR 982, Jan. 10, 1996, unless otherwise noted."
cfr_part: "181"
---


# 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, 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) must have an interconnected fire detection system in compliance with § 181.450 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 of this chapter.

[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]