The HSE defines a prohibition sign as being displayed to prohibit behaviour “likely to increase or cause danger”. UK law dictates that prohibition health and safety signs must feature a circle with red edging on a white background. In specific cases this can also include a black pictogram to visually enhance the message.
Examples include access signs such as “Do not enter”, machinery safety signs including "Do not touch", or legal health instructions like “No smoking”.
In general, prohibition signage messages tend to contain instructions beginning “No” or “Do not”. The message is intended to inform that certain actions are unsafe, or not permitted due to health and safety regulations.
They should be used in the workplace and area accessible to the general public to provide instruction and information on dangerous behaviour that should be stopped immediately and is not allowed.