Thieves prowling the streets of Tokyo’s Ginza and Shinjuku entertainment districts overnight are not so much interested in luxury goods these days as they are targeting the waste leftover from making tempura and "tonkatsu" pork cutlets.

Increasingly, these bandits are swiping up used deep-frying oil as demand for it skyrockets. And it is typically left just sitting out in plain sight.

Restaurants leave 18-liter cans of used cooking oil outside their storefronts when they close for the night so recycling dealers can drop by later to collect them. More and more often, however, the cans are missing when these dealers make their rounds.

And criminals are not the only ones after the now coveted commodity, once seen as a throw-away byproduct from cooking.

“We used to charge fees to dispose of used cooking oil as industrial waste,” said one Tokyo-based recycling agent. “The oil has since surged in price, so now we must pay to collect it. And so many people have entered the market.”

ONE PERSON’S TRASH …

The price suddenly began to rise sometime around spring last year as exports rose. Cooking oil is derived from plants and gets reused when it is burned as fuel, so it is regarded as a good source of renewable energy.

And waste cooking oil can be used as a raw material for making aviation jet fuel, an attractive commodity for an industry that has fallen under scrutiny for emitting large volumes of carbon dioxide.

Demand for it is high in Europe. But Japan exports the largest amount of its waste oil to Singapore, which hosts a plant that produces “sustainable aviation fuel.” Trade statistics show export volumes to the city-state have grown steadily since 2018 to 42,000 tons in 2021. That is 2.3 times what it was just three years earlier.

Waste oil exports to Singapore have also risen in price, shooting up from 68 yen (50 cents) per kilogram to 97 yen per kg during the same period. It averaged 159 yen per kg during the first six months of this year.

Officials of UCO Japan, which organizes and coordinates waste cooking oil collectors and recycling agents, said some 400,000 tons of used cooking oil gets recovered from food plants, restaurants, convenience stores and other establishments across Japan every year.

Japan exported some 120,000 tons of that amount in 2021, up 33 percent from 2020.

DOMESTIC MARKET OUT OF WHACK

But the price hike has thrown Japan’s domestic market for waste cooking oil into chaos.

Cooking oil that was used to prepare school lunches in Kobe, the capital of Hyogo Prefecture, was going for 22 yen per kg when the city government offered public tenders for fiscal 2020. But the successful bid was even higher--30.2 yen per kg for fiscal 2021 and 70.5 yen per kg for fiscal 2022.

Likewise, the sale price of used cooking oil more than doubled year on year to 49.5 yen per kg for fiscal 2022 in Sagamihara, Kanagawa Prefecture.

The city government there is collecting similar oil from general households as one form of recyclable waste and is receiving increasing inquiries about buying used cooking oil from general households. But the quality of the oil varies more than oil used in food plants or to cook school lunches.

The surging prices are also causing supply problems for other similar oils used by domestic industries.

The volume of supply used to make livestock feed--which makes up the bulk of domestic demand for used cooking oil--remains largely unchanged at 200,000 tons a year, while soap, paint and other products made with oil are getting the short end of the stick, officials said.

The company Marusho, based in Tokyo’s Adachi Ward, has been collecting waste cooking oil from local governments, food plants, restaurants and other sources in the Tokyo metropolitan area for about 50 years. It has been shipping the oil mainly for use as a raw material for printing ink.

Demand is growing for similar oils, but all the company can do at the moment is to continue to supply its regular customers, Marusho officials said.

The rising price of cooking oil has prompted a trend to reduce its use, which is also taking a toll on it, the officials added.

“We have received proposals to repurpose some of our oil for export,” Marusho President Mitsuyoshi Fukano said. “But our foremost priority lies on continuing to supply customers who have purchased from us in the past.”

BOON FOR HOUSEHOLD RECYCLING

In late July, senior UCO Japan officials toured pick-up spots for waste cooking oil at supermarkets and public facilities in Sapporo, the capital of Hokkaido.

The authorities of the northern city have been collecting the used oil from households across 370 drop-off locations since 2006. They each have a box to collect the waste cooking oil set up next to recycling bins for recovering cartons and plastic bottles.

The bins are filled with plastic beverage bottles, salad oil containers and other kinds of bottles containing oils of varying hues of brown. The Sapporo city government collects about 240,000 liters of waste oil each year, the most of any city in Japan, officials said.

Around 500 to 600 visitors every month provide some 300 to 400 liters of used cooking oil to a typical supermarket collection drop-off, said Shinichi Maeda, president of Oil Recycle, a company that collects waste cooking oil at about 300 of the recovery points.

Supermarkets are jumping at the chance to host waste oil collection boxes because “those who leave used cooking oil in a recycling box at a supermarket also end up shopping there,” Maeda added.

With hopes that demand will continue to grow, UCO Japan officials are attempting to tap into the country’s rich “urban oil fields.” The company set up an “underused resource development” project for collecting similar waste oils from households. UCO estimates homes produce about 100,000 tons a year.