Placards and Labels according 49 CFR 173.2

General Guidelines on Use of Warning Labels and Placards

See 49 CFR §172 Subpart E for complete labeling regulations.

The Hazardous Materials Table [49 CFR §172.101 Col. 6] identifies the proper label(s) for the hazardous material listed.
Any person who offers a hazardous material for transportation MUST label the package, if required [49 CFR §172.400(a)].
Labels may be affixed to packages when not required by regulations, provided each label represents a hazard of the material contained in the package [49 CFR §172.401].
For labeling mixed or consolidated packages, see 49 CFR §172.404
The appropriate hazard class or division number must be displayed in the lower corner of a primary and subsidiary hazard label [49 CFR §172.402(b)].
For classes 1,2,3,4,5,6, and 8, text indicating a hazard (e.g., “CORROSIVE”) is NOT required on a primary or subsidiary label. The label must otherwise conform to 49 CFR §172 Subpart E [49 CFR §172.405].
Labels must be printed on or affixed to the surface of the package near the proper shipping name marking [49 CFR §172.406(a)].
When primary and subsidiary labels are required, they must be displayed next to each other [49 CFR §172.406(c)].
For a package containing a Division 6.1, PG III material, the POISON label specified in 49 CFR §172.430 may be modified to display the text PG III instead of POISON or TOXIC. Also see 49 CFR §172.313.

See 49 CFR §172 Subpart F for complete placarding regulations.

Each person who offers for transportation or transports any hazardous material subject to the Hazardous Materials Regulations must comply with all applicable requirements of 49 CFR §172 Subpart F [49 CFR §172.500].
Placards may be displayed for a hazardous material, even when not required, if the placarding otherwise conforms to the requirements of Subpart F of Part 172 [49 CFR §172.502(c)].
For other than Class 7 or the DANGEROUS placard, text indicating a hazard (e.g., “FLAMMABLE”) is not required. Text may be omitted from the OXYGEN placard only if the specific ID number is displayed on the placard [49 CFR §172.519(b)(3)].
For a placard corresponding to the primary or subsidiary hazard class of a material, the hazard class or division number must be displayed in the lower corner of the placard.
Any bulk packaging, freight container, unit load device, transport vehicle or rail car containing any quantity of material listed in Table 1 must be placarded [49 CFR §172.504].
When the aggregate gross weight of all hazardous materials in non-bulk packages covered in Table 2 is less than 454 kg (1,001 lbs), no placard is required on a transport vehicle or freight container when transported by highway or rail [49 CFR §172.504(c)].
Notes: See 49 CFR §172.504(f)(10) for placarding Division 6.1, PG III materials.
Placarded loads require registration with USDOT. See 49 CFR §107.601 for registration regulations.

Category of material (Hazard Class or division number and additional description, as appropriate)	Placard name
1.1	EXPLOSIVES 1.1
1.2	EXPLOSIVES 1.2
1.3	EXPLOSIVES 1.3
2.3	POISON GAS
4.3	DANGEROUS WHEN WET
5.2 (Organic peroxide, Type B, liquid or solid, temperature controlled)	ORGANIC PEROXIDE
6.1 (Materials poisonous by inhalation (see §171.8 of this subchapter))	POISON INHALATION HAZARD
7 (Radioactive Yellow III label only)	RADIOACTIVE RADIOACTIVE placard also required for exclusive use shipments of low specific activity material and surface contaminated objects transported in accordance with §173.427(a)(6).

Category of material (Hazard Class or division number and additional description, as appropriate)	Placard name
1.4	EXPLOSIVES 1.4
1.5	EXPLOSIVES 1.5
1.6	EXPLOSIVES 1.6
2.1	FLAMMABLE GAS
2.2	NON-FLAMMABLE GAS
3	FLAMMABLE
Combustible Liquid	COMBUSTIBLE
4.1	FLAMMABLE SOLID
4.2	SPONTANEOUSLY COMBUSTIBLE
5.1	OXIDIZER
5.2 (Other than organic peroxide, Type B, liquid or solid, temperature controlled)	ORGANIC PEROXIDE
6.1 (Other than materials poisonous by inhalation)	POISON
6.2	(None)
8	CORROSIVE
9	CLASS 9 (see §172.504(f)(9))
ORM-D	(None)