Mr. Ouch

[1] Mr. Ouch is similar in name, purpose, and concept to the UPMC Children's Hospital of Pittsburgh's "Mr. Yuk" design[2] used to label poisonous substances, although the two symbols were developed independently.

The design shows a snarling, octopus-like creature with jagged, lightning-bolt arms throwing a child backwards.

[3][4] In early 1981, several member companies of NEMA began studying how to prevent young children from being electrocuted by electrical transformers.

This followed incidents where transformer cabinets were vandalized or left unlocked, allowing access to the high-voltage equipment inside and resulting in disfigurement and death.

[4][1] At the beginning of the project, the task force reached out to transformer manufacturers in an effort to build consensus for standardizing a design.

[6] The test groups were located in Chicago, IL and San Antonio, Texas, and consisted of an equal number of English and non-English-speaking children, aged 2.5 to 6 years old, both boys and girls.

The accompanying text message went beyond just stating the hazard posed, high voltage electricity; and included a clear statement of the consequences, how to avoid them, and what to do if the equipment wasn't secured.

Ouch' labels, are ground level electrical equipment, often pad-mounted transformers, that are accessible by members of the public, such as those situated in residential neighborhoods, parks, shopping centers, and near schools.

[1] The label for use on the external housing of equipment uses the "Warning" signal word, for situations that could result in serious injury or death, and referred to "Hazardous voltage inside" and "Can shock, burn...".