HazMat Tool — substance information

Alkaline earth metal amalgams, solid

HMT 15 June 2026

UN / ID: UN 3402
Hazard class: 4.3
Packing group: I
ERG guide: ERG 138
Special provisions: SP A19, SP N34, SP N40, SP T9, SP TP7, SP TP33, SP W31
Source: 49 CFR §172 (15 June 2026)

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Alkaline earth metal amalgams, solid

In chemistry, an alkali ( ; from the Arabic word al-qily, القالِي "saltwort") also base is a hydroxide of any of either the alkali metal which are Group I s-block elements, or the alkaline earth metal which are Group II s-block. Alkali can also be defined as a base that dissolves in water. A solution of a soluble base has a pH greater than 7.0. The adjectives alkaline and, less often, alkalescent are commonly used in English as a synonyms for basic, especially for bases soluble in water Wikipedia

Emergency Response Guide No. 138

Hazardous Materials Table

Source: 49 CFR §172 (15 June 2026)

(3) Hazard Class

4.3
Dangerous when wet materials

(4) Identification number

UN 3402

(5) Packing Group

(6) Labels

Cargo Aircraft Only (Cargo Aircraft Only)

(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.

A19

Combination packagings consisting of outer fiber drums or plywood drums, with inner plastic packagings, are not authorized for transportation by aircraft.

Browse special provision A19

N34

Aluminum construction materials are not authorized for any part of a packaging which is normally in contact with the hazardous material.

Browse special provision N34

N40

This material is not authorized in the following packagings:
a. A combination packaging consisting of a 4G fiberboard box with inner receptacles of glass or earthenware;
b. A single packaging of a 4C2 sift-proof, natural wood box; or
c. A composite packaging 6PG2 (glass, porcelain or stoneware receptacles within a fiberboard box).

Browse special provision N40

Minimum test pressure (bar)	4
Minimum shell thickness	6 mm
Pressure-relief requirements	Normal
Bottom opening requirements	Prohibited for liquids.

Browse special provision T9

TP7

The vapor space must be purged of air by nitrogen or other means.

Browse special provision TP7

TP33

The portable tank instruction assigned for this substance applies for granular and powdered solids and for solids which are filled and discharged at temperatures above their melting point which are cooled and transported as a solid mass. Solid substances transported or offered for transport above their melting point are authorized for transportation in portable tanks conforming to the provisions of portable tank instruction T4 for solid substances of packing group III or T7 for solid substances of packing group II, unless a tank with more stringent requirements for minimum shell thickness, maximum allowable working pressure, pressure-relief devices or bottom outlets are assigned in which case the more stringent tank instruction and special provisions shall apply. Filling limits must be in accordance with portable tank special provision TP3. Solids meeting the definition of an elevated temperature material must be transported in accordance with the applicable requirements of this subchapter.

Browse special provision TP33

W31

Non-bulk packagings must be hermetically sealed.

Browse special provision W31

(8) Packing Authorizations (§173.***)

(8A) Exceptions	None
(8B) Non-bulk	211	see 49 CFR §173.211
(8C) Bulk	242	see 49 CFR §173.242

(9) Quantity Limits

(9A) Passenger aircraft/rail	Forbidden
(9B) Cargo aircraft only	15 kg

(10) Vessel stowage

(10A) Location

Stowage category “D” means the material must be stowed “on deck only” on a cargo vessel or on a passenger vessel carrying a number of passengers limited to not more than the larger of 25 passengers or one passenger per each 3 m of overall vessel length, but the material is prohibited on a passenger vessel in which the limiting number of passengers is exceeded.

Source: 49 CFR §172.101(k)

(10B) Other

13	see 49 CFR §176.84
52	see 49 CFR §176.84
148	see 49 CFR §176.84

Source: 49 CFR §176.84

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 3482	Alkali metal dispersions, flammable or Alkaline earth metal dispersions, flammable	4.3
UN 1391	Alkali metal dispersions, or Alkaline earth metal dispersions	4.3
UN 1392	Alkaline earth metal amalgams, liquid	4.3
UN 3205	Alkaline earth metal alcoholates, n.o.s	4.2
UN 1393	Alkaline earth metal alloys, n.o.s	4.3