Researchers in Hong Kong are working to cut off a major source of marine plastics: polystyrene (PS) foam boxes widely used in the fishing industry. Scientific research shows that PS is harmful to marine life and human health, but the fishing industry has been slow to respond. The problem is that alternative materials must be as simple to use and inexpensive as PS for widespread adoption. One typical PS product is the white, foamy material known as polystyrene foam, widely used in various food containers, coffee cups, bean bags, and even insulation materials. An industry report shows that PS production reached 17.5 million tons in 2014, one of the most widely used materials globally. More than 40% of this was consumed in the Asia-Pacific region. Dr. Chelsea Rochman, a marine ecologist at the University of Toronto, stated, "If there's one type of plastic we can avoid using, it's polystyrene. Polystyrene foam is one of the most common types of waste washed ashore; this material is not sustainable, so there's no reason to continue using it." The problem begins at the production stage. PS (polystyrene) is polymerized from styrene and benzene, and then foamed to create foamed plastic. Both styrene and benzene are known carcinogens. In addition, toxic flame retardants are sometimes added to foamed plastic products. These toxic substances leach from the plastic products during heating, therefore environmentalists worldwide recommend against using PS in food packaging. A survey by the US-based organization Clean Water Action shows that approximately 80% of marine debris originates from land. And 90% of floating debris in the ocean is made of plastic, traveling globally with the five major currents. Sunlight, salt, and water corrode plastic, eventually breaking it down into extremely small particles. These microplastics are about the size of plankton, enter the marine food chain, and ultimately end up on our dinner tables. As early as 30 years ago, the US Environmental Protection Agency found polystyrene residue in 100% of its collected human adipose tissue samples. The disposal of PS waste is a problem because no one is willing to recycle it. Plastics Recyclers Europe is an association of 120 industry members. Bernard Merkx, the association's honorary chairman, stated, "It's not that PS can't be recycled, but rather that its value is too low; its weight and limited applicability make it seem not worthwhile to recycle." Dr. Rochman explained that PS, especially expanded polystyrene (EPS), is too small and bulky to be worthwhile to recycle. "Recycling dumping fees are calculated by the pound. EPS takes up a lot of space but is lightweight, so the actual recycling rate is very low." Unrecycled plastics end up in landfills, but in countries with poor waste management, landfill waste often ends up in the ocean. Given the challenges of recycling PS, people decided to change direction and try alternative materials. However, PS boxes are not only lightweight and inexpensive but also easy to carry. Therefore, suitable alternative materials must also possess similar characteristics. Polypropylene (PP) is a PS alternative plastic that combines flexibility and insulation. Although PP packaging boxes are more expensive to produce, they have gained favor with recycling companies. In other words, used PP packaging boxes have higher residual value. The latest data from the Association of Plastics Recyclers shows that the annual post-consumer recycling rate of PP products is less than 1%, while the annual demand in North America alone reaches 454,000 tons. The International Solid Waste Federation (ISWA) points out that there are many reasons for such a low recycling rate. The main reasons are the inconsistent quality of recyclable materials and insufficient recycling infrastructure. ISWA also mentioned the lack of international quality standards. Currently, virgin PP is generally more affordable than various recycled materials, but this situation may change in the future as more and more plastic products are recycled. The low recycling rate means that a large portion of PP still ends up in the ocean. After a coastal cleanup operation in the South China Sea in 2015, researchers found that almost 60% of small plastic waste was PP. Although PP material is relatively inert and is a hydrocarbon, so it doesn't release toxic substances like polystyrene, replacing PS with PP requires perfecting recycling facilities and collection processes; otherwise, it's simply replacing one type of plastic pollution with another. Currently, foamed PP is gradually replacing foamed PS globally. Foamed PP is particularly easy to use and has resistance to minor impacts, and it has already gained widespread application and acceptance in the automotive industry. In the fisheries sector, the initial replacement and trial results are very optimistic. Fisheries professionals are very willing to listen to our suggestions. After all, when it comes to the impact of marine environmental pollution, fisheries bear the brunt. Source: Chinadialogue (2017-11-15) (Compiled by PIDC)
