NVIC 03-95: Inspection and testing of fixed halon cylinders
Last reviewed: October 14, 2026
This Navigation and Vessel Inspection Circular is Coast Guard guidance on periodic inspection and testing of fixed halon fire extinguishing system storage cylinders. It publishes requirements equivalent to existing ones and offers an alternative to routine periodic hydrostatic testing. The text given here does not include the enclosure with the detailed procedures.
Applies toThe text applies to halon fire extinguishing system storage cylinders aboard merchant vessels.
What it says
The Circular's purpose is to publish periodic inspection and testing requirements for halon fire extinguishing system storage cylinders that are equivalent to those in 46 CFR Chapter I and NVIC 6-72.
“The purpose of this Circular is to publish periodic inspection and testing”
The Circular says carbon dioxide cylinders can corrode inside because of water vapor and carbonic acid.
NVIC 03-95 a.“These constituents can cause internal corrosion in steel cylinders.”
The Circular says bromotrifluoromethane gas does not cause corrosion of steel.
NVIC 03-95 a.“Bromotrifluoromethane gas does not cause corrosion of steel.”
The Circular says the United States Navy studied hydrostatic testing of halon cylinders on its vessels and concluded that routine testing was generally not necessary.
NVIC 03-95 b.“concluded that routine hydrostatic testing was generally not necessary.”
The Circular says NFPA 12A no longer requires routine hydrostatic testing and instead requires external visual examinations to monitor cylinder corrosion.
NVIC 03-95 c.“requirements no longer require routine hydrostatic testing and instead require external”
Enclosure (1) is an alternative to the periodic testing requirements for fixed halon fire extinguishing system storage cylinders.
NVIC 03-95 a.“Enclosure (1) is an alternative to the periodic testing requirements for fixed halon fire extinguishing system storage cylinders.”
Common questions
What is NVIC 3-95 about?
It publishes periodic inspection and testing requirements for halon fire extinguishing system storage cylinders. They are equivalent to those in 46 CFR Chapter I and NVIC 6-72.
“The purpose of this Circular is to publish periodic inspection and testing”
Does NVIC 3-95 require routine hydrostatic testing of halon cylinders?
The Circular offers enclosure (1) as an alternative to the periodic testing requirements for these cylinders. It says NFPA 12A no longer requires routine hydrostatic testing.
“Enclosure (1) is an alternative to the periodic testing requirements for fixed halon fire extinguishing system storage cylinders.”
Why does halon not need the same testing as carbon dioxide cylinders?
The Circular says bromotrifluoromethane gas does not cause corrosion of steel, unlike the constituents found in carbon dioxide cylinders.
“Bromotrifluoromethane gas does not cause corrosion of steel.”
The text of NVIC 03-95
U.S. Coast Guard, NVIC 03-95 (main body; enclosures not shown)
Periodic Inspection and Testing of Fixed Halon Fire Fighting Equipment Aboard Merchant Vessels
COMDTPUB P16700.4 NVIC 3-95 19 JUNE 1995 NAVIGATION AND VESSEL INSPECTION CIRCULAR NO. 3-95 Electronic Version for Distribution on the World Wide Web Subj: PERIODIC INSPECTION AND TESTING OF FIXED HALON FIRE FIGHTING EQUIPMENT ABOARD MERCHANT VESSELS
Periodic Inspection and Testing of Fixed Halon Fire Fighting Equipment Aboard Merchant Vessels — PURPOSE. The purpose of this Circular is to publish periodic inspection and testing
requirements equivalent to those given in 46 CFR Chapter I and Navigation and Vessel Inspection Circular (NVIC) 6-72, Part VI, enclosure (1) as amended by Change 1 published 28 February 1977, applicable to halon fire extinguishing system storage cylinders.
Periodic Inspection and Testing of Fixed Halon Fire Fighting Equipment Aboard Merchant Vessels — DIRECTIVES AFFECTED: None
DIRECTIVES AFFECTED: None
Periodic Inspection and Testing of Fixed Halon Fire Fighting Equipment Aboard Merchant Vessels — BACKGROUND:
a. Original requirements for periodic hydrostatic testing and inspection of shipboard fixed halon fire extinguishing system cylinders paralleled those in place for carbon dioxide system cylinders. However, carbon dioxide gas cylinders often contain small quantities of water vapor and carbonic acid in solution with carbon dioxide gas. These constituents can cause internal corrosion in steel cylinders. Halon fire extinguishing cylinders contain bromotrifluoromethane (CBrF) and a super pressurization charge of dry nitrogen. Bromotrifluoromethane gas does not cause corrosion of steel. (Cylinders used to ship pure CBrF are exempt from hydrostatic testing under 49 CFR 173.) Nitrogen used in halon cylinders is obtained from air liquefaction and distillation processes that produce nitrogen sufficiently free from moisture that it does not cause corrosion. b. The United States Navy studied the need for hydrostatic testing of halon cylinders on its vessels and concluded that routine hydrostatic testing was generally not necessary. c. The National Fire Protection Association (NFPA) publishes a standard for the design, installation and use of fixed halon fire extinguishing systems, NFPA 12A. This standard is widely used throughout North America for land based halon systems. NFPA standard 12A prescribes periodic inspection and testing requirements for halon systems. These requirements no longer require routine hydrostatic testing and instead require external visual examinations to monitor cylinder corrosion.
Periodic Inspection and Testing of Fixed Halon Fire Fighting Equipment Aboard Merchant Vessels — DISCUSSION.
a. Enclosure (1) is an alternative to the periodic testing requirements for fixed halon fire extinguishing system storage cylinders. This alternative testing and inspection policy should reduce costs associated with routine periodic hydrostatic cylinder testing, replacement of lost halon, cylinder transportation and system down time.
Sections it refers to
- 46 CFR Chapter I
- NVIC 6-72
- 49 CFR 173
The plain-English explanation on this page was written with AI from the regulation text above and checked automatically before publishing: every quote appears in the text, every number comes from it, and a second model confirmed each statement adds nothing the text doesn't say. The regulation text governs. RegKnot is not affiliated with the U.S. Coast Guard.