HazMat Tool — substance information

Xylyl bromide, liquid

HMT 15 June 2026

UN / ID: UN 1701
Hazard class: 6.1
Packing group: II
ERG guide: ERG 152
Special provisions: SP A3, SP A7, SP IB2, SP N33, SP T7, SP TP2, SP TP13, SP W31
Source: 49 CFR §172 (15 June 2026)

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Xylyl bromide, liquid

Xylyl-bromide, also known as methylbenzyl bromide or T-stoff ('substance-T'), is any member or a mixture of organic chemical compounds with the molecular formula C6H4(CH3)(CH2Br). The mixture was formerly used as a tear gas and has an odor reminiscent of lilac. All members and the mixture are colourless liquids, although commercial or older samples appear yellowish Wikipedia

Substance Data

Source: PubChem (HSDB, 04.12.2019)

CAS-Number

104-81-4

Flash Point

n/a

Boiling Point

n/a

Emergency Response Guide No. 152

Hazardous Materials Table

Source: 49 CFR §172 (15 June 2026)

(3) Hazard Class

6.1
Poisonous Material

(4) Identification number

UN 1701

(5) Packing Group

(6) Labels

Cargo Aircraft Only (Cargo Aircraft Only)

(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.

For combination packagings, if glass inner packagings (including ampoules) are used, they must be packed with absorbent material in tightly closed rigid and leakproof receptacles before packing in outer packagings.

Browse special provision A3

Steel packagings must be corrosion-resistant or have protection against corrosion.

Browse special provision A7

IB2

_{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

N33

Aluminum drums are not authorized.

Browse special provision N33

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

TP2

a. The maximum degree of filling must not exceed the degree of filling determined by the following:
TP2a

Where:
t_r is the maximum mean bulk temperature during transport,
t_f is the temperature in degrees celsius of the liquid during filling, and
α is the mean coefficient of cubical expansion of the liquid between the mean temperature of the liquid during filling (t_f) and the maximum mean bulk temperature during transportation (t_r) both in degrees celsius.
b. For liquids transported under ambient conditions α may be calculated using the formula:
TP2b

Where:
d₁₅ and d₅₀ are the densities (in units of mass per unit volume) of the liquid at 15 °C (59 °F) and 50 °C (122 °F), respectively.

Browse special provision TP2

TP13

Self-contained breathing apparatus must be provided when this hazardous material is transported by sea.

Browse special provision TP13

W31

Non-bulk packagings must be hermetically sealed.

Browse special provision W31

(8) Packing Authorizations (§173.***)

(8A) Exceptions	None
(8B) Non-bulk	340	see 49 CFR §173.340
(8C) Bulk	None

(9) Quantity Limits

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

(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

40	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.

Note: The HMR prohibit only those Division 6.1 liquids that meet the definition of a Packing Group (PG) I and Hazard Zone A. See special provision 1 and PHMSA Interpretation #09-0252.

Packages with POISON or POISON INHALATION HAZARD labels, or a POISON label displaying “PG III,” or “PG III” marked next to a POISON label may not be transported with foodstuffs, feed or any other edible material, intended for humans or animals. For exceptions see 49 CFR §177.841(e).

Scope & sources (important)Click to show CFR references

This check evaluates segregation per 49 CFR §177.848. Additional loading/unloading and handling requirements may still apply; see 49 CFR §177 Subpart B (Loading and Unloading):

§177.834 - General requirements
§177.835 - Class 1 materials
§177.837 - Class 3 materials
§177.838 - Class 4 (flammable solid) materials, Class 5 (oxidizing) materials, and Division 4.2 (pyroforic liquid) materials
§177.839 - Class 8 (corrosive) materials
§177.840 - Class 2 (gases) materials
§177.841 - Division 6.1 and Division 2.3 materials
§177.842 - Class 7 (radioactive) material
§177.843 - Contamination of vehicles

Similar substances

UN / ID	Proper shipping name	Hazard class
UN 1647	Methyl bromide and ethylene dibromide mixtures, liquid	6.1
	Methyl bromide and chloropicrin mixtures with more than 2 percent chloropicrin, see Chloropicrin and methyl bromide mixtures
UN 1581	Chloropicrin and methyl bromide mixtures	2.3
	Methyl bromide and chloropicrin mixtures with not more than 2 percent chloropicrin, see Methyl bromide
UN 1928	Methyl magnesium bromide, in ethyl ether	4.3
	Ethylene dibromide and methyl bromide liquid mixtures, see Methyl bromide and ethylene dibromide, liquid mixtures
UN 2576	Phosphorus oxybromide, molten	8
UN 3417	Xylyl bromide, solid	6.1
UN 1716	Acetyl bromide	8
UN 1099	Allyl bromide	3
UN 1725	Aluminum bromide, anhydrous	8
UN 2580	Aluminum bromide, solution	8
UN 1555	Arsenic bromide	6.1
UN 1737	Benzyl bromide	6.1
UN 2692	Boron tribromide	8