HazMat Tool — substance information

Chloroacetic acid, molten

HMT May 2026

UN / ID: UN 3250
Hazard class: 6.1
Packing group: II
ERG guide: ERG 153
Special provisions: SP IB1, SP T7, SP TP3, SP TP28
Source: 49 CFR §172 (2026/05)

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Chloroacetic acid, molten

Chloroacetic acid, industrially known as monochloroacetic acid (MCA), is a organochlorine compound and carboxylic acid with the formula ClCH2CO2H; it is the simplest of the chloroacetic acids. This colorless solid is a useful building block in organic synthesis. Wikipedia

Substance Data

Source: PubChem (HSDB, 15.12.2019)

CAS-Number

79-11-8

Flash Point

n/a

Boiling Point

n/a

Emergency Response Guide No. 153

Hazardous Materials Table

Source: 49 CFR §172 (2026/05)

(3) Hazard Class

6.1
Poisonous Material

(4) Identification number

UN 3250

(5) Packing Group

(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.

IB1

Authorized IBCs: Metal (31A, 31B and 31N).
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 IB1

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

TP3

The maximum degree of filling (in %) for solids transported above their melting points and for elevated temperature liquids shall be determined by the following:
TP3

Where: d_f and d_r are the mean densities of the liquid at the mean temperature of the liquid during filling and the maximum mean bulk temperature during transport respectively.

Browse special provision TP3

TP28

A portable tank having a minimum test pressure of 2.65 bar (265 kPa) may be used provided the calculated test pressure is 2.65 bar or less based on the MAWP of the hazardous material, as defined in §178.275, where the test pressure is 1.5 times the MAWP.

Browse special provision TP28

(8) Packing Authorizations (§173.***)

(8A) Exceptions	None
(8B) Non-bulk	202	see 49 CFR §173.202
(8C) Bulk	243	see 49 CFR §173.243

(9) Quantity Limits

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

(10) Vessel stowage

(10A) Location

Stowage category “C” means the material must be stowed “on deck only” on a cargo vessel or on a passenger vessel.

Source: 49 CFR §172.101(k)

(10B) Other

40	see 49 CFR §176.84
53	see 49 CFR §176.84
58	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 1764	Dichloroacetic acid	8
UN 1839	Trichloroacetic acid	8
UN 2564	Trichloroacetic acid, solution	8
UN 1751	Chloroacetic acid, solid	6.1
UN 1750	Chloroacetic acid, solution	6.1
UN 3416	Chloroacetophenone, liquid, (CN)	6.1
UN 1697	Chloroacetophenone, solid, (CN)	6.1