China's growing online food delivery industry has generated an increasing amount of plastic waste including utensils, takeout containers and bags, according to an internet consulting center. And a business insider estimated that the problem will worsen.

Unlike plastic bottles that end up in recycling systems, takeout waste has to be burned or buried with other trash because it is usually stained with food particles such as gravy or seasoning, so nobody will recycle them, researchers and a business insider said.

In response, they call for an improved recycling system and unification of takeout packaging material.

According to the China Internet Network Information Center, a consulting institute based in Beijing, 406 million users ordered food online last year, up 18.2 percent from 2017.

Meituan, one of the two food delivery platform giants, estimated that last year the number of daily online orders nationwide on average was about 35 million, up nearly 43 percent from 2017.

Sang Meng, former manager of takeout of an international chain restaurant chain, said that those orders were responsible for about 1 million metric tons of plastic waste last year.

Meanwhile, Ocean Conservancy, a nonprofit environmental organization based in the United States, estimated that every year 8 million tons of plastic waste enter global oceans, contributing to the roughly 150 million tons currently circulating in our marine environment.

According to Sang, in the next few years, the online food delivery industry will still experience double-digit growth. However, it is harder to recycle takeout packages than other plastic wastes.

"It is more expensive to recycle them because most Chinese dishes have gravy or soup in them like boiled pork slices, and recyclers need to clean takeout boxes. The additional process would cost 3 yuan ($0.43) to recycle a box. And no one would do that because one box sells for just 0.27 yuan. It's not profitable," Sang said.

A worker at a garbage station in Beijing, who only gave his surname as Jiang, said he would never pick up any takeout plastic trash because it's worthless.

"I just sort out plastic bottles because I can sell them to recycling stations for 0.07 yuan per bottle. No station would like to buy takeout plastic waste because it is dirty," he said.

Zhang Miao, founder of R Cubic, a consulting company working on waste management, said that there were factories recycling takeout trash but the amount was small because the biggest challenge is cleaning the containers.

"As I know, most of the takeout trash ends up in incineration plants and is burned with other trash, which could generate harmful gas. Since it is unrealistic to forbid the use of plastic packages, it is better to develop technology to recycle them," she said.

Sang agrees and said that despite the current high cost, recycling is still a rather important trend.

"If we use this plastic in a recyclable way, pollution would be largely reduced when you compare it to how much is created by plastic that is used only once," he said.

In addition to the improvement of the recycling system, Sang said it is also vital to regulate plastic manufacturers to produce packages that meet quality control.

"If all the plastic packages are made of certain materials, it will be easier to recycle them. However, small restaurants are less likely to use packages that are more expensive but meet standards. So we need to take food packaging materials into consideration when ranking restaurants on platforms such as Meituan or Eleme," he said.

The consideration is that restaurants that don't use environmentally friendly packaging would be ranked lower than those that do on food takeout platforms.

"But either Meituan or Eleme hopes restaurants do business on their platform. To compete for them, the two are not likely to introduce this ranking rule. So a third party must be introduced to supervise the ranking operation," he said.