HazMat Tool — substance information

Oxidizing solid, water reactive, n.o.s

HMT May 2026

UN / ID: UN 3121
Hazard class: 5.1
Packing group: I (multiple — see tabs)
ERG guide: ERG 144
Special provisions: SP 62
Source: 49 CFR §172 (2026/05)

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Oxidizing solid, water reactive, n.o.s

Emergency Response Guide No. 144

Hazardous Materials Table

Source: 49 CFR §172 (2026/05)

Packing group I
Packing group II

(3) Hazard Class

5.1
Oxidizers

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.

62	Oxygen generators (see §171.8) are not authorized for transportation under this entry. Browse special provision 62

(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

n/a

see

(10B) Other

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

Source: 49 CFR §176.84

(3) Hazard Class

5.1
Oxidizers

(4) Identification number

UN 3121

(5) Packing Group

Comparison View of PG

(6) Labels

(1) Symbols

(7) Special Provisions (§172.102)

62	Oxygen generators (see §171.8) are not authorized for transportation under this entry. Browse special provision 62

(8) Packing Authorizations (§173.***)

(8A) Exceptions	152	see 49 CFR §173.152
(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

n/a

see

(10B) Other

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

Source: 49 CFR §176.84

Packing group comparison

Multiple packing groups apply to this entry. See assignment criteria in 49 CFR §173 Subpart D. Details are in the tabs above; differences are highlighted.

	PG I	PG II
1	G	G
2	Oxidizing solid, water reactive, n.o.s	Oxidizing solid, water reactive, n.o.s
3	5.1	5.1
4	UN 3121	UN 3121
5	I	II
6	5.1, 4.3	5.1, 4.3
7	62	62
8A	None	152
8B	214	214
8C	214	214
9A	Forbidden	Forbidden
9B	Forbidden	Forbidden
10A	n/a	n/a
10B	13, 148	13, 148

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 3490	Toxic by inhalation liquid, water-reactive, flammable, n.o.s. with an LC50 lower than or equal to 200 ml/m3 and saturated vapor concentration greater than or equal to 500 LC50	6.1
UN 3491	Toxic by inhalation liquid, water-reactive, flammable, n.o.s. with an LC50 lower or equal to 1000 ml/m3 and saturated vapor concentration greater than or equal to 10 LC50	6.1
UN 3386	Toxic by inhalation liquid, water-reactive, n.o.s. with an LC50 lower than or equal to 1000 ml/m3 and saturated vapor concentration greater than or equal to 10 LC50	6.1
UN 3385	Toxic by inhalation liquid, water-reactive, n.o.s. with an LC50 lower than or equal to 200 ml/m3 and saturated vapor concentration greater than or equal to 500 LC50	6.1
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 3232	Self-reactive solid type B, temperature controlled	4.1
UN 3234	Self-reactive solid type C, temperature controlled	4.1
UN 3236	Self-reactive solid type D, temperature controlled	4.1
UN 3238	Self-reactive solid type E, temperature controlled	4.1
UN 3240	Self-reactive solid type F, temperature controlled	4.1
UN 3393	Organometallic substance, solid, pyrophoric, water-reactive	4.2
UN 3396	Organometallic substance, solid, water-reactive, flammable	4.3
UN 3397	Organometallic substance, solid, water-reactive, self-heating	4.3
UN 3394	Organometallic substance, liquid, pyrophoric, water-reactive	4.2
UN 3399	Organometallic substance, liquid, water-reactive, flammable	4.3