Subsidiary placards

Scope

Anyone who is responsible for placarding a transport vehicle, freight container, portable tank, unit load device, or rail car must follow the subsidiary placarding requirements.

Regulatory citations

• 49 CFR 172.505 — Placarding for subsidiary hazards

Key definitions

• Primary hazard: The hazard class of a material as assigned in the 172.101 table.
• Subsidiary hazard: The hazard of a material other than the primary hazard.

Summary of requirements

Generally, only the primary placards are displayed. However, 172.505 of the hazardous materials regulations requires additional placards to be displayed under certain conditions for several subsidiary hazards. The following subsidiary placards must be displayed:

• POISON GAS,
• POISON INHALATION HAZARD,
• POISON,
• CORROSIVE, and
• DANGEROUS WHEN WET.

Other subsidiary placards are permitted to be displayed but are not required.

Subsidiary placards, just like primary placards, must have the hazard class or division number in the lower corner of the placard.