Merino wool, a natural fibre grown by Merino sheep in Australia and
championed as a sustainable alternative to synthetics, does not contribute
to the issue of microplastics in our oceans, according to new research from
The Woolmark Company.
The ‘Microfibre Pollution and the Marine Biodegradation of Wool’ study
found that both untreated and machine washable wool readily biodegrade in
marine environments, while synthetic fibres do not.
The issue of plastic microfibres and their harmful impact on the
environment has become a growing focus for the fashion industry in recent
years. Between half a million and a million tonnes of plastic microfibres are
released into wastewater every year from the washing of synthetic clothes,
according to Common Objective.
The Woolmark Company’s study compared the biodegradability of both
untreated and machine washable Merino wool in sea water with the biodegradability of viscose rayon,
polyester, nylon and polypropylene using scanning electron microscopy and
energy-dispersive X-ray spectroscopy. All the fabrics were washed repeatedly
before testing to reflect a “partial garment lifetime” and the
rate of biodegradation was compared to that of kraft paper pulp, a
substance known to biodegrade readily.
Machine washable wool biodegrades faster than untreated wool
The Woolmark Company’s report found that machine washable wool
biodegrades at a faster rate than untreated wool fabrics and that there was
no evidence that treated wool’s polyamide resin coating – which is added to
prevent shrinkage – contributed to microplastic pollution.
The report found that untreated wool biodegraded at 20.3 percent the
rate of the pulp, while the machine-washable wool biodegraded more than
three times as quickly, at a rate of 67.3 per cent – the fastest of all
fabrics.
Nylon biodegraded at the slowest rate of the fibres tested at just 0.8
percent, followed by polypropylene and polyester.
The Woolmark Company managing director Stuart McCullough commented in
the report: “Our research into wool and microplastics began back in 2016
when we investigated the current state of knowledge concerning microplastic
pollution, focussing on microfibres from textiles. This initial body of
research began the process of improving methodological development to
account for microfibre release during the use phase in the Lifecycle
Assessment of clothing.
“This latest scientific study is a significant addition to the body of
research investigating the damage certain textiles cause to our
environment. Wool has long been heralded the original eco fibre, but
concerns had been raised about the machine-washable finish applied to wool
and whether it added to the microplastic problem, so we wanted to clarify
that issue.
“During these ever-changing troubled times it’s important to
consider how well-intentioned consumers can make purchasing decisions that
help look after the health of the environment. Choosing natural fibres,
such as Merino wool is an important place to start.”
Photo credit: Woolmark Company’s Live & Breathe campaign |
Stuart McCullough & Chart courtesy of AWI