HazMat Tool — substance information Reference only — not a shipping paper, placard mandate, or CVI record.

Signals, smoke

HMT 15 June 2026

UN / ID: UN 0197
Hazard class: 1.4G
Packing group: —
ERG guide: —
Special provisions: —
Source: 49 CFR §172 (15 June 2026)

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Signals, smoke

A signal is both the process and the result of transmission of data over some media accomplished by embedding some variation. Signals are important in multiple subject fields, including signal processing, information theory and biology. In signal processing, a signal is a function that conveys information about a phenomenon. Any quantity that can vary over space or time can be used as a signal to share messages between observers Wikipedia

Hazardous Materials Table

Source: 49 CFR §172 (15 June 2026)

(3) Hazard class

1.4
Explosives

(4) Identification number

UN 0197

(5) Packing Group

—

(6) Labels

Compatibility group of explosives - Description of substances or article to be classified

Group: G

Pyrotechnic substance or article containing a pyrotechnic substance, or article containing both an explosive substance and an illuminating, incendiary, tear-producing or smoke-producing substance (other than a water-activated article or one containing white phosphorus, phosphide or flammable liquid or gel or hypergolic liquid).

Source: 49 CFR §173.52

Cargo Aircraft Only (Cargo Aircraft Only)

(7) Special Provisions (§172.102)

(8) Packing Authorizations (§173.***)

(8A) Exceptions	None
(8B) Non-bulk	62	see 49 CFR §173.62
(8C) Bulk	None

(9) Quantity Limits

(9A) Passenger aircraft/rail	Forbidden
(9B) Cargo aircraft only	75 kg

(10) Vessel stowage

(10A) Location

Stowage category “02” means the material may be stowed “on deck” in closed cargo transport units or “under deck” on a cargo vessel (up to 12 passengers) or “on deck” in closed cargo transport units or “under deck” in closed cargo transport units on a passenger vessel.

Source: 49 CFR §172.101(k)

(10B) Other

25	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.

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 0493	Signals, railway track, explosive	1.4G
UN 0492	Signals, railway track, explosive	1.3G
UN 0193	Signals, railway track, explosive	1.4S
UN 0192	Signals, railway track, explosive	1.1G
UN 0505	Signals, distress, ship	1.4G
UN 0506	Signals, distress, ship	1.4S
UN 0195	Signals, distress, ship	1.3G
UN 0194	Signals, distress, ship	1.1G