A white cross on green, marking first aid provision.
Also known as: First aid sign, Green cross, Medical aid sign, First aid post
A white cross on a green square marks first aid. The colour is the whole point: a red cross on white is the protected emblem of the Red Cross movement, and using it for ordinary first aid is a misuse of a Geneva Conventions emblem.
Marks first aid equipment, a first aid room, or a person trained to give first aid.
Contexts: Public information
Is green rather than red because the red cross on a white ground is a protected emblem under the Geneva Conventions, restricted to the Red Cross and Red Crescent movement and to medical services in armed conflict.
This is the reason the colours cannot be swapped. Using a red cross to mark an ordinary first aid kit misuses a protected emblem, however common the practice is in commercial packaging.
Contexts: Public information
Shares the safe-condition green with the emergency exit symbol, marking where help is rather than where a hazard is.
Contexts: Public information
Belongs to the safe-condition class of safety signs, drawn as a white pictogram on a green square or rectangle. Green marks where safety is — an exit, a route, equipment for helping someone — and never a hazard.
Contexts: Public information
A white upright cross with four equal arms, centred on a solid green square.
Both are safe-condition signs, which is why both are green.