HazMat Tool — substance information Reference only — not a shipping paper, placard mandate, or CVI record.

Articles containing a substance which in contact with water emits flammable gases, n.o.s.

HMT 15 June 2026

UN / ID: UN 3543
Hazard class: 4.3
Packing group: —
ERG guide: —
Special provisions: SP 131, SP 391
Source: 49 CFR §172 (15 June 2026)

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Articles containing a substance which in contact with water emits flammable gases, n.o.s.

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Hazardous Materials Table

Source: 49 CFR §172 (15 June 2026)

(3) Hazard class

4.3
Dangerous when wet materials

(4) Identification number

UN 3543

(5) Packing Group

—

(6) Labels

(1) Symbols

This entry is signed with "G". The letter "G" identifies proper shipping names for which one or more technical names of the hazardous material must be entered in parentheses, in association with the basic description. (See §172.203(k)).

(7) Special Provisions (§172.102)

×Note:
Special provisions may be very complex. The extracts are taken from 49 CFR §172.102. Please be careful with the information, as necessary, additional conditions may be applied that are not written here. Please check the original source and report bugs.

131	This material may not be offered for transportation unless approved by the Associate Administrator. Browse special provision 131
391	Except for articles being transported by motor vehicle as a material of trade in accordance with § 173.6 of this subchapter, articles containing hazardous materials of Division 2.3, or Division 4.2, or Division 4.3, or Division 5.1, or Division 5.2, or Division 6.1 (substances with an inhalation toxicity of Packing Group I) and articles containing more than one of the following hazards: (1) Gases of Class 2; (2) Liquid desensitized explosives of Class 3; or (3) Self-reactive substances and solid desensitized explosives of Division 4.1, may only be offered for transportation and transported under conditions approved by the Associate Administrator. Browse special provision 391

(8) Packing Authorizations (§173.***)

(8A) Exceptions	None
(8B) Non-bulk	214	see 49 CFR §173.214
(8C) Bulk	214	see 49 CFR §173.214

(9) Quantity Limits

(9A) Passenger aircraft/rail	Forbidden
(9B) Cargo aircraft only	Forbidden

(10) Vessel stowage

(10A) Location	—
(10B) Other	—

Segregation chart for load, transport, and storage

This chart shows whether loading, transport, or storage with other hazard classes is permitted, prohibited, or restricted. Based on 49 CFR §177.848.

Hazard class	8	7	6.1	5.2	5.1	4.3	4.2	4.1	3	2.3B	2.3A	2.2	2.1	1.6	1.5	1.4	1.3	1.1/1.2
1.1/1.2
1.3
1.4
1.5
1.6
2.1
2.2
2.3A
2.3B
3
4.1
4.2
4.3
5.1
5.2
6.1
7
8

	Must not be loaded, transported, or stored together in the same vehicle or facility.
	May be loaded, transported, or stored together.
	May be loaded, transported, or stored together only with restrictions.

Similar substances

UN / ID	Proper shipping name	Hazard class
UN 0222	Ammonium nitrate, with more than 0.2 percent combustible substances, including any organic substance calculated as carbon, to the exclusion of any other added substance	1.1D
UN 1942	Ammonium nitrate, with not more than 0.2% combustible substances, including any organic substance calculated as carbon, to the exclusion of any other added substance	5.1
UN 3476	Fuel cell cartridges or Fuel cell cartridges contained in equipment or Fuel cell cartridges packed with equipment, containing water-reactive substances	4.3
UN 3477	Fuel cell cartridges or Fuel cell cartridges contained in equipment or Fuel cell cartridges packed with equipment, containing corrosive substances	8
UN 0341	Nitrocellulose, unmodified or plasticized with less than 18 percent plasticizing substance, by mass	1.1D
NA 1693	Tear gas devices with more than 2 percent tear gas substances, by mass	6.1
	Formaldehyde solutions (with not less than 10% and less than 25% formaldehyde), see Aviation regulated liquid, n.o.s. or Other regulated substances, liquid, n.o.s.
UN 0343	Nitrocellulose, plasticized with not less than 18 percent plasticizing substance, by mass	1.3C
UN 3399	Organometallic substance, liquid, water-reactive, flammable	4.3
UN 3396	Organometallic substance, solid, water-reactive, flammable	4.3
UN 0482	Substances, explosive, very insensitive, n.o.s. or Substances, EVI, n.o.s.	1.5D
UN 3209	Metallic substance, water-reactive, self-heating, n.o.s	4.3
UN 3394	Organometallic substance, liquid, pyrophoric, water-reactive	4.2
UN 3393	Organometallic substance, solid, pyrophoric, water-reactive	4.2
UN 3397	Organometallic substance, solid, water-reactive, self-heating	4.3