Class 6
Class 6 — toxic and infectious substances
Class 6.1 is toxic substances. Class 6.2 is infectious substances.
Class 6 covers poisonous materials and infectious substances. Division 6.1 is toxic substances. Division 6.2 is infectious substances. The placard is a warning about health hazard, not about fire, though a given chemical can earn more than one placard when the rules require it.
Toxic inhalation hazards sometimes travel with additional markings beyond the class diamond. If you see extra text or a second panel, copy all of it. Don't reduce the car to "poison" and stop.
This is a case where standing close for a better photo is a bad trade. A long lens from a public place is enough to read a placard. The car does not need you next to the manway.
Identification only. If a car is leaking or in a wreck, move away and call your local emergency number. Responders use the Emergency Response Guidebook. This page is not that book.