Canadian researchers turn fish bones and guts into eco-friendly, biodegradable plastic: ‘All you need is 1 gram of fish oil…’

Fish heads and bones can look unappealing, but they can be transformed into something useful and eco-friendly. A research team in Canada invented a new use for fish heads. Other than becoming cat food, fish remains can be used to make plastics. Yes, you read that right! A group of researchers from Memorial University of Newfoundland, Canada, turned fish guts and bones into a polyurethane-like polymer that could offer a more sustainable path for making everyday materials. Conventional manufacturing depends on crude oil and hazardous phosgene, producing isocyanates that may cause skin and respiratory irritation. The resulting substance is also known for being particularly hard to biodegrade, increasing its environmental impact.

As per a report by the Royal Society of Chemistry, the team invented a three-step process to create plastic from oil extracted from fish guts and bones.

The Process To Turn Fish Into Plastic


Initially, they utilised hydrogen peroxide to oxidise the fish oil; subsequently, they combined it with carbon dioxide, and ultimately, they reacted it with an amine. The end result is a film-like substance that has an orange or red hue, is somewhat elastic, and does not emit a fishy smell. The team started with an amine derived from cashew nutshell waste, a material available for purchase, but graduate student researcher Mikhailey Wheeler has since effectively replaced it with amino acids, which streamlines the chemistry process. Initial findings indicate that histidine and asparagine may replace the amine obtained from cashew nutshells by connecting the elements of the polymer. To date, the biggest plastic piece produced by the team is a film measuring up to 3 cm².

Was The Plastic Biodegradable?

To examine the biodegradability of the plastic, the team observed it with an electron microscope. The material swelled by 10% when soaked in water, with holes appearing. With the addition of the lipase enzyme, small cracks appeared, and fungi and bacteria began growing on it within a week.

"This degrades faster than conventional polyurethanes because the lipid, the fish oil we are using as a building block, contains esters, and that group is fantastic for encouraging biodegradation because they are very easy to do a hydrolysis reaction on, and that starts to break apart carbon–oxygen and carbon–carbon bonds in the structure,” told chemistry professor Francesca Kerton to the magazine.

Research by Kerton indicates that a single gram of oil extracted from discarded fish material can be converted into approximately 1.4 grams of plastic, with the final yield varying according to the type of amine incorporated into the process. The quantity of fish-derived oil required also decreases as the molecular weight of the amine increases.

Using global fisheries-waste estimates published by the United Nations, the researchers further assessed the potential supply of this raw material. Their analysis indicates that the volume of fish waste generated worldwide could be sufficient to provide the feedstock needed to meet global polyurethane demand.