HazMat Tool — substance information

Barium

HMT 15 June 2026

UN / ID: UN 1400
Hazard class: 4.3
Packing group: II
ERG guide: ERG 138
Special provisions: SP A19, SP IB7, SP IP2, SP IP21, SP T3, SP TP33, SP W31, SP W40
Source: 49 CFR §172 (15 June 2026)

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Barium

Barium is a chemical element; it has symbol Ba and atomic number 56. It is the fifth element in group 2 and is a soft, silvery alkaline earth metal. Because of its high chemical reactivity, barium is never found in nature as a free element. The most common minerals of barium are barite (barium sulfate, BaSO4) and witherite (barium carbonate, BaCO3). The name barium originates from the alchemical derivative "baryta" from Greek βαρὺς (barys), meaning 'heavy' Wikipedia

Substance Data

Source: PubChem (HSDB, 27.11.2019)

CAS-Number

7440-39-3

Flash Point

n/a

Boiling Point

n/a

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 1400

(5) Packing Group

(6) Labels

(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

IB7

_{Authorized IBCs:} Metal (11A, 11B, 11N, 21A, 21B, 21N, 31A, 31B and 31N); Rigid plastics (11H1, 11H2, 21H1, 21H2, 31H1 and 31H2); Composite (11HZ1, 11HZ2, 21HZ1, 21HZ2 and 31HZ1); Wooden (11C, 11D and 11F).
_{Additional Requirement:} Liners of wooden IBCs must be sift-proof.

Browse special provision IB7

IP2

When IBCs other than metal or rigid plastics IBCs are used, they must be offered for transportation in a closed freight container or a closed transport vehicle.

Browse special provision IP2

IP21

When transported by vessel, flexible, fiberboard or wooden IBCs must be sift-proof and water-resistant or be fitted with a sift-proof and water-resistant liner.
Large outer packagings:
Large outer packagings:
§ 178.275(d)(2)
§ 178.275(d)(3)
§ 178.275(d)(2)
§ 178.275(d)(3)
Prohibited
§ 178.275(d)(2)
§ 178.275(d)(3)
Prohibited
Prohibited for liquids.
Prohibited
§ 178.275(d)(3)
§ 178.275(d)(3)
Prohibited
Prohibited
§ 178.275(d)(3)
§ 178.275(d)(3)
§ 178.275(d)(3)
§ 178.275(d)(3)
Prohibited
Prohibited
Prohibited for liquids. § 178.275(d)(2).

Browse special provision IP21

Minimum test pressure (bar)	2.65
Minimum shell thickness	§ 178.274(d)(2)
Pressure-relief requirements	Normal
Bottom opening requirements	§ 178.275(d)(2)

Browse special provision T3

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

W40

Non-bulk bags are not allowed.

Browse special provision W40

(8) Packing Authorizations (§173.***)

(8A) Exceptions	151	see 49 CFR §173.151
(8B) Non-bulk	212	see 49 CFR §173.212
(8C) Bulk	241	see 49 CFR §173.241

(9) Quantity Limits

(9A) Passenger aircraft/rail	15 kg
(9B) Cargo aircraft only	50 kg

(10) Vessel stowage

(10A) Location

Stowage category “E” means the material may be stowed “on deck” or “under deck” 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 is prohibited from carriage 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 0224	Barium azide, dry or wetted with less than 50 percent water, by mass	1.1A
UN 1571	Barium azide, wetted with not less than 50 percent water, by mass	4.1
UN 2741	Barium hypochlorite with more than 22 percent available chlorine	5.1
UN 1854	Barium alloys, pyrophoric	4.2
UN 1445	Barium chlorate, solid	5.1
UN 3405	Barium chlorate, solution	5.1
UN 1564	Barium compounds, n.o.s	6.1
UN 1447	Barium perchlorate, solid	5.1
UN 3406	Barium perchlorate, solution	5.1
UN 2719	Barium bromate	5.1
UN 1565	Barium cyanide	6.1
UN 1446	Barium nitrate	5.1
UN 1884	Barium oxide	6.1
UN 1448	Barium permanganate	5.1
UN 1449	Barium peroxide	5.1