HazMat Tool — substance information

Mercury oxycyanide, desensitized

HMT May 2026

UN / ID: UN 1642
Hazard class: 6.1
Packing group: II
ERG guide: ERG 151
Special provisions: SP IB8, SP IP2, SP IP4, SP T3, SP TP33
Source: 49 CFR §172 (2026/05)

On this page

Mercury oxycyanide, desensitized

Mercury oxycyanide is a chemical compound, an organomercury derivative. It is both explosive and highly toxic, producing symptoms of both mercury and cyanide poisoning following exposure. Wikipedia

Emergency Response Guide No. 151

Hazardous Materials Table

Source: 49 CFR §172 (2026/05)

(3) Hazard Class

6.1
Poisonous Material

(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.

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

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

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)	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

(8) Packing Authorizations (§173.***)

(8A) Exceptions	153	see 49 CFR §173.153
(8B) Non-bulk	212	see 49 CFR §173.212
(8C) Bulk	242	see 49 CFR §173.242

(9) Quantity Limits

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

(10) Vessel stowage

(10A) Location

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

52	see 49 CFR §176.84
91	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 0150	Pentaerythrite tetranitrate, wetted or Pentaerythritol tetranitrate, wetted, or PETN, wetted with not less than 25 percent water, by mass, or Pentaerythrite tetranitrate, or Pentaerythritol tetranitrate or PETN, desensitized with not less than 15 percent phlegmatizer by mass	1.1D
UN 3344	Pentaerythrite tetranitrate mixture, desensitized, solid, n.o.s. or Pentaerythritol tetranitrate mixture, desensitized, solid, n.o.s. or PETN mixture, desensitized, solid, n.o.s., with more than 10 percent but not more than 20 percent PETN, by mass	4.1
UN 0391	RDX and HMX mixtures, wetted with not less than 15 percent water by mass or RDX and HMX mixtures, desensitized with not less than 10 percent phlegmatizer by mass	1.1D
UN 3319	Nitroglycerin mixture, desensitized, solid, n.o.s. with more than 2 percent but not more than 10 percent nitroglycerin, by mass	4.1
UN 3343	Nitroglycerin mixture, desensitized, liquid, flammable, n.o.s. with not more than 30 percent nitroglycerin, by mass	3
UN 0075	Diethyleneglycol dinitrate, desensitized with not less than 25 percent non-volatile water-insoluble phlegmatizer, by mass	1.1D
UN 3357	Nitroglycerin mixture, desensitized, liquid, n.o.s. with not more than 30% nitroglycerin, by mass	3
UN 0143	Nitroglycerin, desensitized with not less than 40 percent non-volatile water insoluble phlegmatizer, by mass	1.1D
UN 0483	Cyclotrimethylenetrinitramine, desensitized or Cyclonite, desensitized or Hexogen, desensitized or RDX, desensitized	1.1D
UN 0484	Cyclotetramethylenetetranitramine, desensitized or Octogen, desensitized or HMX, desensitized	1.1D
	Cyclotrimethylenenitramine and octogen, mixtures, wetted or desensitized see RDX and HMX mixtures, wetted or desensitized, etc
	Cyclonite and cyclotetramethylenetetranitramine mixtures, wetted or desensitized see RDX and HMX mixtures, wetted or desensitized etc
	Cyclonite and HMX mixtures, wetted or desensitized see RDX and HMX mixtures, wetted or desensitized etc
	Cyclonite 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