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Nitrosyl chloride

HMT 15 June 2026

UN / ID: UN 1069
Hazard class: 2.3
Packing group: —
ERG guide: ERG 125
Special provisions: SP 3, SP B14
Source: 49 CFR §172 (15 June 2026)

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Nitrosyl chloride

Nitrosyl chloride is the chemical compound with the formula NOCl. It is a yellow gas that is commonly encountered as a component of aqua regia, a mixture of 3 parts concentrated hydrochloric acid and 1 part of concentrated nitric acid. It is a strong electrophile and oxidizing agent. It is sometimes called Tilden's reagent, after William A Wikipedia

Substance Data

Source: PubChem (HSDB, 22.10.2026)

CAS-Number

2696-92-6

Flash Point

—

Boiling Point

-5.5 ° C

Emergency Response Guide No. 125

Hazardous Materials Table

Source: 49 CFR §172 (15 June 2026)

(3) Hazard class

2.3
Poisonous gas

(4) Identification number

UN 1069

(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.

3	This material is poisonous by inhalation (see § 171.8 of this subchapter) in Hazard Zone C (see § 173.116(a) of this subchapter), and must be described as an inhalation hazard under the provisions of this subchapter. Browse special provision 3
B14	Each bulk packaging, except a tank car or a multi-unit-tank car tank, must be insulated with an insulating material so that the overall thermal conductance at 15.5 °C (60 °F) is no more than 1.5333 kilojoules per hour per square meter per degree Celsius (0.075 Btu per hour per square foot per degree Fahrenheit) temperature differential. Insulating materials must not promote corrosion to steel when wet. Browse special provision B14

(8) Packing Authorizations (§173.***)

(8A) Exceptions	None
(8B) Non-bulk	304	see 49 CFR §173.304
(8C) Bulk	314, 315	see 49 CFR §173.314, 315

(9) Quantity Limits

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

(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.

Hinweis: In der Kompatibilitätstabelle sind Stoffe der Gefahrenklasse 2.3 abhängig der Einstufung der inhalativen Giftigkeit zu berücksichtigen (Gefahrenzone A). Siehe Sonderbestimmung 1 sowie PHMSA Interpretation #09-0252.

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 2308	Nitrosylsulfuric acid, liquid	8
UN 3456	Nitrosylsulphuric acid, solid	8