American designer Anna Meddaugh has created a personal urinal that women in refugee camps can use in shelters at night to avoid the threat of sexual violence outside.

Meddaugh was named runner up in the US James Dyson Award for her prototype, Night Loo, a portable and reusable toilet box with polymer beads that soak up liquid and odours.

In the light and relative safety of day, users can dispose of the contents in a public toilet.

Meddaugh created Night Loo to provide a safe option for women and girls in refugee camps, who have reported feeling too scared to use the provided toilets at night.

"The circumstances within refugee camps can lead to unimaginable choices, having to weigh the likelihood of getting attacked and raped while making your way to the toilet, versus suffering through the night or possibly even soiling yourself," said Meddaugh. "Imagine being faced with this choice every night."

Women sometimes avoid eating or drinking at night or request adult diapers to avoid having to use the facilities at night, the designer said.

She wanted to find a solution that would protect people from harm while preserving their dignity and being practical and simple to use.

Night Loo is a silicone container with flaps that open at the top like a takeaway box. These flaps provide a splashguard when the user squats over the box to use it.

After urinating, the user pours in a sachet of super-absorbent polymer known as Instant Snow. This polymer entirely soaks up the liquid and quickly turns to dry powder, eliminating odour as it does so.

In the morning, the user emptied the contents of the box in the latrines. One side of the box pops out to form a spout, making it easy for them to do so.

Another feature of Night Loo is that it folds flat for efficient cleaning and shipping. Meddaugh describes the product as "tidier and more pleasant than a bedpan or chamber pot".

"It is far more sustainable than disposable urinals or adult diapers – only the absorbed urine is discarded," she said. "The container is durable and reusable."

Meddaugh is pursuing grant funding and technical support to make Night Loo production-ready, and hopes to work with refugee agencies to distribute it as widely as possible.

The James Dyson Award recognises top inventions from current and recent engineering and design graduates from around the world. The winners of the national heats go on to compete in the international competition, with famed British inventor James Dyson picking the grand prize winner on 15 November 2018.

Previous years' winning inventions have included a skin cancer detector that avoids the need for biopsies and a folding paper bicycle helmet.