Sustainable Plastics - January/February 2021 - 27

bioplastics

PHA fermentation inside living microorganisms

Disposable serviceware
from PHA

So, what is PHA again?
Bacteria produce PHA as a
source of energy and as a carbon store through the fermentation of renewable feedstocks
such as sugars or fatty acids,
or any other carbon-containing
substrate. This natural process
can be mimicked in an industrial setting using feedstocks
that can range from wastewater
streams to plastic waste, renewable methane and carbon dioxide. They are a class of natural
materials that have existed in nature for millions of years. These
materials are both bio-based
and biodegradable, similar to
other naturals materials such as
cellulose, proteins and starch.
According to GO!PHA, PHA
products range from amorphous
to highly crystalline, and run
from high-strength, hard and
brittle materials to low-strength,
soft and elastic. The versatility of
the PHA family accommodates
a wide range of market applications, due to their biocompatibility, biodegradability and green
credentials. Depending on type
and grade, PHAs can be used
for injection moulding, extrusion,
thermoforming, foam, non-wovens, fibers, 3D-printing, paper
and fertiliser coating, glues,
adhesives, as additive for reinforcement or plasticisation or
as building block for thermosets
in paints and foams. The main
markets where PHAs have already achieved some degree of
penetration are packaging, food
service, agriculture and medical
products.
PHA is equally versatile

when it comes to the end of
life. It can be reused. It can be
recycled back to the polymer
for new applications. It can be
recycled back to raw materials
to be used as renewable feedstock. It can be recycled to the
environment through industrial
or home composting. It can be
recycled through incineration
creating renewable energy.
And lastly, it can be recycled to
nutrients for living organisms
through full biodegradation.

Drawing the line
PHA may well be a natural polymer, but in the eyes of the EU
it is classified as an artificial or
a modified polymer and hence
not allowed to be used as a single use plastic replacement.
The reason?
" The basic problem is the fact
that PHA is considered to be a
fermentation-based product, "
said Mukherjee.
ECHA considers fermentation - in their REACH Guidelines
- to be an industrial process,
even though, in the EU Legislation on Flavorings, for example,
products produced through fermentation processes are considered to be natural. And what
about cheeses, wine and beer,
or sauerkraut - should these
therefore also be reclassified as
artificial? They, too, are all the
result of fermentation using living organisms.
" Of course: PHA is the result
of a fermentation process. The
point here is that fermentation
is a natural process - one that
occurs everywhere in nature.

PHA is a natural polymer that
is produced by natural routes
in nature, and industrial fermentation processes simply
make them economically viable, " Mukherjee explained.
For commercial purposes,
the process is scaled in order to
be able to produce commercial
volumes, but it remains a bacterial process that produces a
bacterial polyester, he said.
" We have talked to the Commission about this, but with
disappointing results. "
The stance adopted by the
European Commission is even
more puzzling in view of the fact
that Europe has spent over €110
million sponsoring research into
the valorization of waste to produce PHA. One such project -
EUROPHA - developed a PHA
production process using mixed
microbial cultures, enabling the
use of low-cost agro-food waste
with no market value, no food
competition, and no price volatility effects. Further research was
aimed at developing high quality
food-grade biodegradable PHA
for packaging that could be disposed of as organic waste.
Moreover, a recently concluded study by the EU expert
committee entitled " Science
Advice for Policy by European
Academies " on the 'Biodegradability of plastics in the open
environments, SAPEA, December 18, 2020' clearly states
that the field of biodegradable
polymers is one that is rapidly evolving and high-tech and
that 'policy should avoid placing barriers to future developments and innovations.'

Europe versus the world
Outside Europe, PHA is starting to gain real momentum,

with various producers - Kaneka, Newlight Technologies,
Danimer Scientific, for example
- having successfully scaled up
production to industrial or even
commercial levels. Around the
world, it is being used to replace
fossil-based plastics in a host of
single-use plastic applications
such as straws, serviceware,
even coffee pods.
The rest of the world, explained Mukherjee, has designated biodegradability - see,
for example, the SUP legislation passed in China in January
2020 - as the criterion to ban or
exempt use of plastics.
" There are standards for biodegradability - also for marine
biodegradability - that are used
to certify this. The EU is the
only one using this natural polymer criterion to exclude PHA
- but to include cellulose, " said
Mukherjee.
Yet PHA's biodegradability
profile is very similar to cellulose, he pointed out. " Cellulose
and PHA have the same order
of magnitude biodegradation
pattern. All other plastics replacements and biopolymers
are several orders of magnitude
longer in biodegradation. "
It seems odd: other parts
of the world are happy to embrace PHA as a full-fledged
biodegradable,
sustainable
biopolymer and to support
and promote its further development and use in single use
applications. There, the science
is straightforward. Europe, however, continues to tenaciously
adhere to its own criteria and
interpretation of the concept of
'natural' - despite what scientists, including EU's own expert
panel SAPEA, say.
How this will affect future
research and business developments in PHA materials in
Europe remains to be seen, but
there seems little doubt that not
recognising these materials'
potential and eminent suitability for a least some of the products included in the ban, could
at least result in Europe's falling
out of step with measures taken elsewhere. This is surely not
the intention of the directive.
Achieving a clean, non-polluted environment - in the oceans
and on land - demands collaborative, coordinated action.
It is time to get on with it.

January/February 2021

P026_P027_SP_20210209.indd 27

27

1/29/21 12:19 PM



Sustainable Plastics - January/February 2021

Table of Contents for the Digital Edition of Sustainable Plastics - January/February 2021

Contents
Sustainable Plastics - January/February 2021 - Cover1
Sustainable Plastics - January/February 2021 - Cover2
Sustainable Plastics - January/February 2021 - Contents
Sustainable Plastics - January/February 2021 - 4
Sustainable Plastics - January/February 2021 - 5
Sustainable Plastics - January/February 2021 - 6
Sustainable Plastics - January/February 2021 - 7
Sustainable Plastics - January/February 2021 - 8
Sustainable Plastics - January/February 2021 - 9
Sustainable Plastics - January/February 2021 - 10
Sustainable Plastics - January/February 2021 - 11
Sustainable Plastics - January/February 2021 - 12
Sustainable Plastics - January/February 2021 - 13
Sustainable Plastics - January/February 2021 - 14
Sustainable Plastics - January/February 2021 - 15
Sustainable Plastics - January/February 2021 - 16
Sustainable Plastics - January/February 2021 - 17
Sustainable Plastics - January/February 2021 - 18
Sustainable Plastics - January/February 2021 - 19
Sustainable Plastics - January/February 2021 - 20
Sustainable Plastics - January/February 2021 - 21
Sustainable Plastics - January/February 2021 - 22
Sustainable Plastics - January/February 2021 - 23
Sustainable Plastics - January/February 2021 - 24
Sustainable Plastics - January/February 2021 - 25
Sustainable Plastics - January/February 2021 - 26
Sustainable Plastics - January/February 2021 - 27
Sustainable Plastics - January/February 2021 - 28
Sustainable Plastics - January/February 2021 - 29
Sustainable Plastics - January/February 2021 - 30
Sustainable Plastics - January/February 2021 - 31
Sustainable Plastics - January/February 2021 - 32
Sustainable Plastics - January/February 2021 - 33
Sustainable Plastics - January/February 2021 - 34
Sustainable Plastics - January/February 2021 - Cover3
Sustainable Plastics - January/February 2021 - Cover4
https://www.nxtbookmedia.com