HazMat Tool — substance information

Water-reactive solid, toxic, n.o.s

HMT May 2026

UN / ID: UN 3134
Hazard class: 4.3
Packing group: I (multiple — see tabs)
ERG guide: ERG 139
Special provisions: SP A8, SP IB4, SP IP1, SP N40, SP W31
Source: 49 CFR §172 (2026/05)

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Water-reactive solid, toxic, n.o.s

Emergency Response Guide No. 139

Hazardous Materials Table

Source: 49 CFR §172 (2026/05)

Packing group I
Packing group II
Packing group III

(3) Hazard Class

4.3
Dangerous when wet materials

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.

A8	For combination packagings, if glass inner packagings (including ampoules) are used, they must be packed with cushioning material in tightly closed metal receptacles before packing in outer packagings. Browse special provision A8
IB4	Authorized IBCs: Metal (11A, 11B, 11N, 21A, 21B, 21N, 31A, 31B and 31N). Browse special provision IB4
IP1	IBCs must be packed in closed freight containers or a closed transport vehicle. Browse special provision IP1
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
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
148	see 49 CFR §176.84

Source: 49 CFR §176.84

(3) Hazard Class

4.3
Dangerous when wet materials

(4) Identification number

UN 3134

(5) Packing Group

Comparison View of PG

(6) Labels

(1) Symbols

(7) Special Provisions (§172.102)

IB5

Authorized IBCs: Metal (11A, 11B, 11N, 21A, 21B, 21N, 31A, 31B and 31N); Rigid plastics (11H1, 11H2, 21H1, 21H2, 31H1 and 31H2); Composite (11HZ1, 21HZ1 and 31HZ1).

Browse special provision IB5

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

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	242	see 49 CFR §173.242

(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
85	see 49 CFR §176.84
148	see 49 CFR §176.84

Source: 49 CFR §176.84

(3) Hazard Class

4.3
Dangerous when wet materials

(4) Identification number

UN 3134

(5) Packing Group

III

Comparison View of PG

(6) Labels

(1) Symbols

(7) Special Provisions (§172.102)

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).

Browse special provision IB8

IP4

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

Browse special provision IP4

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

Browse special provision T1

TP33

Browse special provision TP33

W31

Non-bulk packagings must be hermetically sealed.

Browse special provision W31

(8) Packing Authorizations (§173.***)

(8A) Exceptions	151	see 49 CFR §173.151
(8B) Non-bulk	213	see 49 CFR §173.213
(8C) Bulk	241	see 49 CFR §173.241

(9) Quantity Limits

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

(10) Vessel stowage

(10A) Location

Source: 49 CFR §172.101(k)

(10B) Other

13	see 49 CFR §176.84
85	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	PG III
1	G	G	G
2	Water-reactive solid, toxic, n.o.s	Water-reactive solid, toxic, n.o.s	Water-reactive solid, toxic, n.o.s
3	4.3	4.3	4.3
4	UN 3134	UN 3134	UN 3134
5	I	II	III
6	4.3, 6.1	4.3, 6.1	4.3, 6.1
7	A8, IB4, IP1, N40, W31	IB5, IP2, T3, TP33, W31, W40	IB8, IP4, T1, TP33, W31
8A	None	151	151
8B	211	212	213
8C	242	242	241
9A	Forbidden	15 kg	25 kg
9B	15 kg	50 kg	100 kg
10A	D	E	E
10B	13, 148	13, 85, 148	13, 85, 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 3125	Toxic solids, water-reactive, n.o.s	6.1
UN 3396	Organometallic substance, solid, water-reactive, flammable	4.3
UN 3397	Organometallic substance, solid, water-reactive, self-heating	4.3
UN 3399	Organometallic substance, liquid, water-reactive, flammable	4.3
UN 3231	Self-reactive liquid type B, temperature controlled	4.1