HazMat Tool — substance information

Hexachlorobutadiene

HMT 15 June 2026

UN / ID: UN 2279
Hazard class: 6.1
Packing group: III
ERG guide: ERG 151
Special provisions: SP IB3, SP T4, SP TP1
Source: 49 CFR §172 (15 June 2026)

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Hexachlorobutadiene

Hexachlorobutadiene, (often abbreviated as "HCBD") Cl2C=C(Cl)C(Cl)=CCl2, is a colorless liquid at room temperature that has an odor similar to that of turpentine. It is a chlorinated aliphatic diene with niche applications but is most commonly used as a solvent for other chlorine-containing compounds. Structurally, it has a 1,3-butadiene core, but fully substituted with chlorine atoms Wikipedia

Substance Data

Source: PubChem (HSDB, 07.12.2019)

CAS-Number

87-68-3

Flash Point

n/a

Boiling Point

n/a

Emergency Response Guide No. 151

Hazardous Materials Table

Source: 49 CFR §172 (15 June 2026)

(3) Hazard Class

6.1
Poisonous Material

(4) Identification number

UN 2279

(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.

IB3

_{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)	2.65
Minimum shell thickness	§ 178.274(d)(2)
Pressure-relief requirements	Normal
Bottom opening requirements	§ 178.275(d)(3)

Browse special provision T4

TP1

The maximum degree of filling must not exceed the degree of filling determined by the following:
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	153	see 49 CFR §173.153
(8B) Non-bulk	203	see 49 CFR §173.203
(8C) Bulk	241	see 49 CFR §173.241

(9) Quantity Limits

(9A) Passenger aircraft/rail	60 L
(9B) Cargo aircraft only	220 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	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.

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