Back to overview

PHAs: A Compostable Alternative to Plastic. 6 Answers to Your FAQs

PHAs: A Compostable Alternative to Plastic. 6 Answers to Your FAQs

Plastic pollution is a problem everywhere. From the plastic bags blowing across our neighborhoods to the island-sized plastic gyres floating in the ocean, we encounter the plastic problem at every scale.

Many are asking what can we do about it? Are there any plastic alternatives that are actually sustainable? What about compostable plastics? Are they really compostable, or is it all just hype to get us to make us think our plastic problem has been solved?  

compostable alternative to plastic, pha
Here are some answers to common questions about plastic and compostable plastic alternatives.


Q: How is PHA made, and why is it different from the other biobased plastic alternatives?


A: Unlike plastic alternatives derived from corn or other crops that are grown just to create bioplastic, FCB uses bacteria to naturally ferment organic waste (like food, dirty cardboard, agricultural byproducts) and produce a regenerative material. Rather than using extra resources to grow crops to create plastic, we are tackling the food waste problem and producing a more sustainable plastic alternative. 

Full Cycle’s waste-to-PHA technology is completely circular; food waste is converted into sustainable packaging solutions and after market use, is upcycled into virgin PHA, then starts all over again. 

Q: Are compostable plastics too good to be true? Are they actually compostable, or is it all just a ploy to get us to buy more plastic?

A: Good question. Many compostable, bio-based (made from organic materials) plastics out there like PLA require special industrial composting facilities to break down, leading to conversations about whether or not they should actually be labeled “compostable”.  

Because traditional PLA requires a particular set of microorganisms that only exist in very high temperatures to degrade – over 140F -, you can’t throw them in your backyard compost bin and expect them to break down like your banana peels and grass clippings. 

Most municipalities don’t have the industrial composting infrastructure needed to break down PLA, and when these bioplastics inevitably end up in the landfill, they tend to stick around like traditional plastics. 

On the other hand, PHA is both compostable and biodegradable, meaning that it will break down without the need for industrial composting facilities. It also won’t leach contaminants into the soil, which end up in our groundwater,  like petroleum-based plastics. PHA and other biopolymers that are in the same family like PHB, PHV, and PHH, will decompose whether they are exposed to compost, soil, or marine sediment. Studies have also shown that, unlike petroleum-based plastics, PHA is biocompatible, meaning it isn’t harmful to living tissue. 

There are a lot of questions around recycling, re-using, and reducing petroleum-based plastic. FCB applauds everyone taking action to reduce food waste & individual plastic use. PHA is a compostable & biodegradable solution made from food waste which plays a significant role in finding a way out of the current plastics & food waste crisis.

FCB is committed to creating sustainable options for companies looking to reduce their negative environmental impact with compostable, biodegradable alternatives to petroleum-based plastic.

compostable alternative to plastic, pha

Q: I thought plastic was recyclable. Why are plastics ending up in the ocean?

A: Unlike what the petroleum-based plastic industry would like you to believe, only about nine percent of plastic is recycled. It’s cheaper to make new petroleum-based plastic than turning used petroleum-based plastics into new things. With petroleum-based plastics that are recycled, they can only be recycled one or two times before they degrade, are unusable, and end up in landfills.

Mismanaged trash that ends up as litter makes its way onto beaches, and into streams and rivers that flow into the ocean. This fugitive litter creates both visible plastic waste that harms marine habitats and an invisible stream of toxic chemicals that contaminate waterways and ultimately show up in the food we eat.

Q: What about PHA? What happens if PHA ends up in waterways?

A: PHA is unique because a plastic film made out of PHA can be composted — food for bacteria— some of which can produce more PHA. Because of this, FCB can create a circular lifecycle rather than a linear one where the plastic ends up in the trash or as litter along roadsides, beaches, and riverways. 

Which leads us to the question: what happens if PHA ends up in our waterways? Various studies have shown that when PHB (a type of PHA Full Cycle produces) is submerged in marine water at a temperature of 30°C, there is 90% biodegradation within a maximum of 6 months. That said, FCB is still actively researching & pursuing certifications to not rely purely on previous literature. 

We can all agree that it is best if our waterways are free of foreign substances, especially since colder oceans with low bacteria loads have a hard time decomposing all organic matter, biodegradable or not. This is why FCB is creating a circular lifecycle for PHA to help keep bioplastics out of landfills and marine environments. Still, if PHA does enter the environment inappropriately, it will self-correct and harmlessly biodegrade. 

Q: If PHA is compostable, why doesn’t it break down when used as a food or beverage container?

A: PHA breaks down quickly in bacteria-heavy environments like compost heaps and waterways because it is a preferred food source for bacteria. Packaging remains stable in places with few bacteria, like supermarket shelves, refrigerators, and delivery trucks.

compostable alternative to plastic, phaQ: What about microplastics? I have been hearing that many bioplastics aren’t actually breaking down completely, they are just turning into microplastics that are even worse for the environment than full-sized plastics.

A: Yes, microplastics are an incredibly important part of this conversation. It is scary to hear that microplastics are ending up in our oceans, lakes, food, and even rainclouds.  Here at FCB we are problem solvers and are working to make sure that we aren’t adding additional waste (even if it is microscopic) to an already out-of-control crisis. 

Petroleum-based plastics and some bioplastics keep the same properties as they break down, so even when they are microscopic, they still have the same chemical properties. Those tiny bits can accumulate in environments and organisms. 

In the same way that we don’t worry about the cellulose fiber from a paper bag breaking down and harming our eco-systems, PHA, when degraded, even if it is a “microplastic” (in terms of size), isn’t biologically harmful. Under aerobic (conditions with oxygen present) conditions, PHA breaks down as CO2 (carbon dioxide) and H2O (water), and under anaerobic (oxygen-free) conditions, it breaks down into CO2 and CH4 (methane gas). 

Q: Whoa, hold on a second – isn’t methane gas the greenhouse gas we are trying to avoid because it contributes to climate change? How is it sustainable if it emits greenhouse gases as it degrades?

A: You are correct; methane is a potent greenhouse gas emitted when organic materials degrade in anaerobic places like landfills. Because of methane’s ability to trap heat, it is a much more potent gas than CO2. Composting creates an oxygen-rich environment for decomposing organic materials and significantly reduces the amount of methane gas emitted by decomposing organic materials.

In addition, when compost is added to soil, it enriches the soil with nutrients, reduces the need for fertilizers, helps soil retain water, less water is required for crops, and protects soil from erosion.

Reducing greenhouse gasses is an important reason Full Cycle creates beginning-of-life and end-of-life solutions via PHA. Full Cycle is diligently developing a circular resolution, converting food waste into sustainable packaging, and recapturing used PHA packaging to upcycle into virgin PHA, reducing food waste, packaging pollution, and greenhouse gas emissions.