There is an EU symbol of "skull and crossbones" for this. This symbol has the difficulty that the Pirate symbol is often used in games and as Sporting Team symbols.
The 'Mr Yuk" symbol from the US has some features to recommend it, but as it is copyright and therefore not in public domain, that counts against it.
Line b
The symbol is As
The symbol for helium is He. The symbol for mercury is Hg.
The symbol for Sulfur is S.The symbol is S
Bi is the symbol for bismuth.
The pound (#) symbol
The traditional symbol of poison is the skull and crossbones (which is also a symbol of piracy, when used on a flag - both poison and piracy are known to be highly lethal).
what symbol identifies motor oil meets tough cma standards
It identifies the element.
coat of arms
It identifies items that are flammable or combustible.
jet streams
Arsenic (atomic symbol As)
毒药/Dúyào
The symbol for a state capital on a map is a circle surrounding a star.
A symbol at the beginning of a formula identifies the entry as a formula instead of a label. In an entry of =B3+C3, the equal sign identifies the entry as a formula.
Yellow Suit