Placards that contain the DOT class number 6 at the bottom identify a material that may be an infectious substance hazard.

• A. True
• B. False
• C. Not Applicable
• D. Unknown

Answer: (A)

Hazard placards convey the type of hazard, and the bottom number identifies the specific class. A bottom number of 6 designates Class 6, which covers toxic substances and infectious substances. Because infectious substances are included in this class, a placard showing a 6 indicates that the material may be an infectious substance hazard. It’s a cue for responders to treat the material with heightened care and use appropriate protective measures. It’s worth noting that not every Class 6 material is infectious—some are purely toxic chemicals—but the possibility of an infectious hazard is present whenever the bottom number is 6.