UN 1824
UN 1824 — sodium hydroxide solution
UN 1824 is sodium hydroxide solution, a class 8 corrosive, and it is a base rather than an acid.
UN 1824 is sodium hydroxide solution, commonly called caustic soda. It is class 8. It is corrosive because it is a strong base, not because it is an acid. Mixing up 1824 and 1830 gets the chemistry backwards.
Caustic service is a normal tank-car job. The placard will not say "caustic" in plain language. It will say 1824 and show an 8. That is the plain language, once you know the number.
The same distance rule applies. You can read 1824 from the public side of the right of way. You don't need to be at the outlet valve.
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.