A Food Rescue project has been launched in Perth to collect and redistribute food to the homeless more effectively.

The project, by Uniting Care West, particularly targets families sleeping in their cars and ensuring homeless children have lunch to take to school.

The project aims to rescue 9,500 kilograms of fresh food a week, equating to about 19,000 meals a week.

The community organisation uses bikes which they reconfigure to work as cargo carts that can fit on footpaths.

Thirty-five cafeterias have agreed to contribute to the cause, with more expected to join.

Food Rescue manager Julie Broad was initially worried about securing 30 volunteers per week, but she said the response from companies was incredible.

"Engineering and project management company Ausenco found out about our project and absolutely loved it," she said.

"That's now [snowballed] into 11 companies... who have volunteered their staff to push carts around the city, collecting the food and bringing it to our food rescue van on St Georges Terrace to be loaded up."

Two carts will operate each day with volunteers from Alinta Energy, Argonaut, Ausenco, Rio Tinto, Bankwest, QBE, Clayton Utz, PwC, Westpac, Business News and Brookfield Corporate Offices taking part in the daily runs.

Ms Broad said the central location makes it easy for volunteers to take part.

"They can leave their office desks and come down to get their carts and off they go with a run sheet to collect from the participating cafes," she said.

"The wooden carts covered with logos and big wheels are like a Rolls Royce of carts to be honest."

Ms Broad said the cargo carts are a more environmentally friendly method of collecting leftover food from cafes in the city than a van.

"With the size of the city and the increase of traffic on the roads, it's just become increasingly difficult to rescue leftover wraps and rolls from cafes," she said.

"We had these cargo carts which were in fact bikes, and we configured them to work as cargo carts to enable volunteers to push them on the footpath."

Abiding by strict guidelines set by the Health Department, "rescued" food is kept in temperature-controlled cooler boxes and covered in ice blankets with infra-red guns to test the quality of food at points of collection and during handover.

The collected food is then distributed by Food Rescue's refrigerated vans to homeless support centres including Manna Inc, The Salvos, the Tranby Inner City Centre and Family Foundation Services.