46 CFR § 154.1848 - Inerting.

---
identifier: "/us/cfr/t46/s154.1848"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "46 CFR § 154.1848 - Inerting."
title_number: 46
title_name: "Shipping"
section_number: "154.1848"
section_name: "Inerting."
chapter_name: "COAST GUARD, DEPARTMENT OF HOMELAND SECURITY"
subchapter_number: "O"
subchapter_name: "CERTAIN BULK DANGEROUS CARGOES"
part_number: "154"
part_name: "SAFETY STANDARDS FOR SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES"
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. 3703, 9101; Department of Homeland Security Delegation No. 0170.1."
regulatory_source: "CGD 74-289, 44 FR 26009, May 3, 1979, unless otherwise noted."
cfr_part: "154"
---


# 154.1848 Inerting.

(a) The master shall ensure that:

(1) Hold and interbarrier spaces on a vessel with full secondary barriers are inerted so that the oxygen concentration is 8 percent or less by volume when flammable cargoes are carried;

(2) Hold and interbarrier spaces contain only dry air or inert gas on:

(i) A vessel with partial secondary barriers;

(ii) A vessel with full secondary barriers when non-flammable cargoes are carried; and

(iii) A vessel with refrigerated independent tanks type C;

(3) When cargo tanks containing flammable vapor are to be gas freed, the flammable vapors are purged from the tank by inert gas before air is admitted; and

(4) When gas free cargo tanks are to be filled with a flammable cargo, air is purged from the tank by inert gas until the oxygen concentration in the tank is 8 percent or less by volume before cargo liquid or vapor is introduced.

(b) Inert gas must be supplied from the shore or from the vessel's inert gas system.