HazMat Tool — substance information

Trimethylamine, aqueous solutions with not more than 50 percent trimethylamine by mass

HMT 15 June 2026

UN / ID: UN 1297
Hazard class: 3
Packing group: I (multiple — see tabs)
ERG guide: ERG 132
Special provisions: SP T11, SP TP1
Source: 49 CFR §172 (15 June 2026)

Spot an error in this entry?

On this page

Trimethylamine, aqueous solutions with not more than 50 percent trimethylamine by mass

Trimethylamine (TMA) is an organic compound with the formula N(CH3)3. It is a trimethylated derivative of ammonia. TMA is widely used in industry. At higher concentrations it has an ammonia-like odor, and can cause necrosis of mucous membranes on contact Wikipedia

Substance Data

Source: PubChem (HSDB, 07.12.2019)

CAS-Number

75-50-3

Flash Point

n/a

Boiling Point

n/a

Emergency Response Guide No. 132

Hazardous Materials Table

Source: 49 CFR §172 (15 June 2026)

Packing group I
Packing group II
Packing group III

(3) Hazard Class

3
Flammable liquids

(4) Identification number

UN 1297

(5) Packing Group

I

Comparison View of PG

(6) Labels

Flammable liquids (3)

Corrosive liquids (8)

(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.

Minimum test pressure (bar)	6
Minimum shell thickness	§ 178.274(d)(2)
Pressure-relief requirements	Normal
Bottom opening requirements	§ 178.275(d)(3)

Browse special provision T11

The maximum degree of filling must not exceed the degree of filling determined by the following:
TP1

TP1

Where:
t_r is the maximum mean bulk temperature during transport, and t_f is the temperature in degrees celsius of the liquid during filling.

Browse special provision TP1

(8) Packing Authorizations (§173.***)

(8A) Exceptions	None
(8B) Non-bulk	201	see 49 CFR §173.201
(8C) Bulk	243	see 49 CFR §173.243

(9) Quantity Limits

(9A) Passenger aircraft/rail	0.5 L
(9B) Cargo aircraft only	2.5 L

(10) Vessel stowage

(10A) Location

D

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

40	see 49 CFR §176.84
52	see 49 CFR §176.84
135	see 49 CFR §176.84

Source: 49 CFR §176.84

(3) Hazard Class

3
Flammable liquids

(4) Identification number

UN 1297

(5) Packing Group

II

Comparison View of PG

(6) Labels

Flammable liquids (3)

Corrosive liquids (8)

(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.

If the material has a flash point at or above 38 °C (100 °F) and below 93 °C (200 °F), then the bulk packaging requirements of § 173.241 of this subchapter are applicable. If the material has a flash point of less than 38 °C (100 °F), then the bulk packaging requirements of § 173.242 of this subchapter are applicable.

Browse special provision B1

_{Authorized IBCs:} Metal (31A, 31B and 31N); Rigid plastics (31H1 and 31H2); Composite (31HZ1).
_{Additional Requirement:} Only liquids with a vapor pressure less than or equal to 110 kPa at 50 °C (1.1 bar at 122 °F), or 130 kPa at 55 °C (1.3 bar at 131 °F) are authorized.

Browse special provision IB2

Minimum test pressure (bar)	4
Minimum shell thickness	§ 178.274(d)(2)
Pressure-relief requirements	Normal
Bottom opening requirements	§ 178.275(d)(3)

Browse special provision T7

The maximum degree of filling must not exceed the degree of filling determined by the following:
TP1

TP1

Where:
t_r is the maximum mean bulk temperature during transport, and t_f is the temperature in degrees celsius of the liquid during filling.

Browse special provision TP1

(8) Packing Authorizations (§173.***)

(8A) Exceptions	150	see 49 CFR §173.150
(8B) Non-bulk	202	see 49 CFR §173.202
(8C) Bulk	243	see 49 CFR §173.243

(9) Quantity Limits

(9A) Passenger aircraft/rail	1 L
(9B) Cargo aircraft only	5 L

(10) Vessel stowage

(10A) Location

B

Stowage category “B” means

(i) The material may be stowed “on deck” or “under deck” on a cargo vessel and 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; and
(ii) “On deck only” on passenger vessels in which the number of passengers specified in paragraph (k)(2)(i) of this section is exceeded.

Source: 49 CFR §172.101(k)

(10B) Other

40	see 49 CFR §176.84
41	see 49 CFR §176.84
52	see 49 CFR §176.84

Source: 49 CFR §176.84

(3) Hazard Class

3
Flammable liquids

(4) Identification number

UN 1297

(5) Packing Group

III

Comparison View of PG

(6) Labels

Flammable liquids (3)

Corrosive liquids (8)

(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.

If the material has a flash point at or above 38 °C (100 °F) and below 93 °C (200 °F), then the bulk packaging requirements of § 173.241 of this subchapter are applicable. If the material has a flash point of less than 38 °C (100 °F), then the bulk packaging requirements of § 173.242 of this subchapter are applicable.

Browse special provision B1

_{Authorized IBCs:} Metal (31A, 31B and 31N); Rigid plastics (31H1 and 31H2); Composite (31HZ1 and 31HA2, 31HB2, 31HN2, 31HD2 and 31HH2).
_{Additional Requirement:} Only liquids with a vapor pressure less than or equal to 110 kPa at 50 °C (1.1 bar at 122 °F), or 130 kPa at 55 °C (1.3 bar at 131 °F) are authorized, except for UN2672 (also see special provision IP8 in Table 2 for UN2672).

Browse special provision IB3

Minimum test pressure (bar)	4
Minimum shell thickness	§ 178.274(d)(2)
Pressure-relief requirements	Normal
Bottom opening requirements	§ 178.275(d)(3)

Browse special provision T7

The maximum degree of filling must not exceed the degree of filling determined by the following:
TP1

TP1

Where:
t_r is the maximum mean bulk temperature during transport, and t_f is the temperature in degrees celsius of the liquid during filling.

Browse special provision TP1

(8) Packing Authorizations (§173.***)

(8A) Exceptions	150	see 49 CFR §173.150
(8B) Non-bulk	203	see 49 CFR §173.203
(8C) Bulk	242	see 49 CFR §173.242

(9) Quantity Limits

(9A) Passenger aircraft/rail	5 L
(9B) Cargo aircraft only	60 L

(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

40	see 49 CFR §176.84
41	see 49 CFR §176.84
52	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
2	Trimethylamine, aqueous solutions with not more than 50 percent trimethylamine by mass	Trimethylamine, aqueous solutions with not more than 50 percent trimethylamine by mass	Trimethylamine, aqueous solutions with not more than 50 percent trimethylamine by mass
3	3	3	3
4	UN 1297	UN 1297	UN 1297
5	I	II	III
6	3, 8	3, 8	3, 8
7	T11, TP1	B1, IB2, T7, TP1	B1, IB3, T7, TP1
8A	None	150	150
8B	201	202	203
8C	243	243	242
9A	0.5 L	1 L	5 L
9B	2.5 L	5 L	60 L
10A	D	B	A
10B	40, 52, 135	40, 41, 52	40, 41, 52

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 0072	Cyclotrimethylenetrinitramine, wetted or Cyclonite, wetted or Hexogen, wetted or RDX, wetted with not less than 15 percent water by mass	1.1D
UN 0483	Cyclotrimethylenetrinitramine, desensitized or Cyclonite, desensitized or Hexogen, desensitized or RDX, desensitized	1.1D
	2,4,6-Trinitrophenyl trimethylol methyl nitramine trinitrate (dry)	Forbidden
	Cyclotrimethylenenitramine and octogen, mixtures, wetted or desensitized see RDX and HMX mixtures, wetted or desensitized, etc
	Cyclotrimethylenetrinitramine and cyclotetramethylenetetranitramine mixtures, wetted or desensitized see RDX and HMX mixtures, wetted or desensitized etc
	Cyclotrimethylenetrinitramine and HMX mixtures, wetted or desensitized see RDX and HMX mixtures, wetted or desensitized etc
	Methyl trimethylol methane trinitrate	Forbidden
UN 1083	Trimethylamine, anhydrous	2.1
	Trimethylol nitromethane trinitrate	Forbidden
	Trimethylene glycol diperchlorate	Forbidden