HazMat Tool — substance information

Magnesium nitrate

HMT May 2026

UN / ID: UN 1474
Hazard class: 5.1
Packing group: III
ERG guide: ERG 140
Special provisions: SP 332, SP A1, SP B120, SP IB8, SP IP3, SP T1, SP TP33
Source: 49 CFR §172 (2026/05)

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Magnesium nitrate

Magnesium nitrate refers to inorganic compounds with the formula Mg(NO3)2(H2O)x, where x = 6, 2, and 0. All are white solids. The anhydrous material is hygroscopic, quickly forming the hexahydrate upon standing in air. All of the salts are very soluble in both water and ethanol. Wikipedia

Emergency Response Guide No. 140

Hazardous Materials Table

Source: 49 CFR §172 (2026/05)

(3) Hazard Class

5.1
Oxidizers

(4) Identification number

UN 1474

(5) Packing Group

III

(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.

332

Magnesium nitrate hexahydrate is not subject to the requirements of this subchapter.

Browse special provision 332

Single packagings are not permitted on passenger aircraft.

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B120

The use of flexible bulk containers conforming to the requirements in subpart R and subpart S of part 178 of this subchapter is permitted.

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IB8

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); Fiberboard (11G); Wooden (11C, 11D and 11F); Flexible (13H1, 13H2, 13H3, 13H4, 13H5, 13L1, 13L2, 13L3, 13L4, 13M1 or 13M2).

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IP3

Flexible IBCs must be sift-proof and water-resistant or must be fitted with a sift-proof and water-resistant liner.

Browse special provision IP3

Minimum test pressure (bar)	1.5
Minimum shell thickness	§ 178.274(d)(2)
Pressure-relief requirements	Normal
Bottom opening requirements	§ 178.275(d)(2)

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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

(8) Packing Authorizations (§173.***)

(8A) Exceptions	152	see 49 CFR §173.152
(8B) Non-bulk	213	see 49 CFR §173.213
(8C) Bulk	240	see 49 CFR §173.240

(9) Quantity Limits

(9A) Passenger aircraft/rail	25 kg
(9B) Cargo aircraft only	100 kg

(10) Vessel stowage

(10A) Location	A Stowage category “A” means the material may be stowed “on deck” or “under deck” on a cargo vessel or on a passenger vessel. Source: 49 CFR §172.101(k)
(10B) Other	n/a

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 1869	Magnesium or Magnesium alloys with more than 50 percent magnesium in pellets, turnings or ribbons	4.1
UN 2950	Magnesium granules, coated, particle size not less than 149 microns	4.3
UN 1459	Chlorate and magnesium chloride mixture solid	5.1
UN 3407	Chlorate and magnesium chloride mixture solution	5.1
UN 1418	Magnesium, powder or Magnesium alloys, powder	4.3
UN 1928	Methyl magnesium bromide, in ethyl ether	4.3
	Magnesium dross, wet or hot	Forbidden
UN 1419	Magnesium aluminum phosphide	4.3
UN 1622	Magnesium arsenate	6.1
UN 1473	Magnesium bromate	5.1
UN 2723	Magnesium chlorate	5.1
UN 2004	Magnesium diamide	4.2
UN 2853	Magnesium fluorosilicate	6.1
UN 2010	Magnesium hydride	4.3
UN 1475	Magnesium perchlorate	5.1