Dressing as a nurse this Halloween? Adding a red cross breaks the law.

As Halloween revelers prepare to take to the streets in nurse uniforms and other costumes, the Japanese Red Cross Society is warning that using the iconic red cross emblem without authorization is against the law — even as a costume accessory.

The emblem, often mistaken for a general symbol of medical care, is protected under international and domestic laws and is reserved for specific humanitarian purposes.

The Red Cross emblem was established under the Geneva Conventions to identify people and facilities that must not be attacked during armed conflicts. Japan’s law on the Red Cross emblem also prohibits anyone other than the Japanese Red Cross Society and those authorized by it from using the symbol without permission. Violators face up to six months in prison or a fine of up to ¥300,000 ($1,900).

“The Red Cross emblem is not a symbol of medical care. It is a last lifeline in times of emergency,” said Akihiko Saito, an official at the Japanese Red Cross Society.

The organization warns that casual use of the emblem during peacetime could undermine its significance when it is needed most. Since 2022, the organization has issued annual reminders on social media around Halloween urging people not to use the symbol on costumes or accessories.

Japanese Red Cross Society's examples of red cross emblems that are prohibited for use without authorization | Japanese Red Cross Society / via Jiji

The emblem is not limited to a specific color or cross shape. This is intended to prevent people or facilities from being attacked simply because they cannot reproduce the exact design amid the confusion of armed conflict.

Similar symbols are also prohibited, including crosses in shades of red such as pink and crosses of varying shapes. The organization cautions that people should also avoid using the emblem on nurse uniforms, caps and even medicine boxes.

MalyMoon, a cosplay costume retailer with stores in Tokyo’s Akihabara district and Shanghai, offers 40 types of nurse costumes for this year’s Halloween. The company uses heart motifs and accessories such as toy syringes to evoke the look without using the Red Cross emblem.

“We were aware that using the red cross emblem was prohibited, but the Japanese Red Cross Society’s warning has reminded us to be even more careful,” an official at a company operating the store said.