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Biodegradable Plastic: Is It REALLY Eco-Friendly?

If there’s one environmental claim that makes me nervous when I see it printed on plastic-like products and packaging, it’s “biodegradable”. Why? Because without context, this label is vague and potentially misleading.

A one-word label like this tells us nothing about the true biodegradability of a product. What does it biodegrade into? Toxic or non-toxic? How long does the process actually take?

Yet companies plaster it on their products in an effort to make us believe they are more eco-friendly. As customers, we gravitate towards these products, as we want to make better choices.

For the average shopper, it’s hard to pick out the good claims from the bad ones.

This post will help make some sense of it all.

What Does “Biodegradable” Mean?

The process of biodegradation is influenced by a number of conditions, including temperature, humidity, oxygen levels, presence of bacteria and time.

Biodegradation is a chemical process in which materials are metabolised into water, carbon dioxide, and biomass by microorganisms. Depending on the material, toxic residues may remain.

But what does “biodegradable” mean when it’s printed on packaging, or on the label of a product?

There is actually no single common understanding or definition of “biodegradable”, so different companies will mean different things when they use this label. That makes it pretty confusing for us.

We might assume that if a product is labelled “biodegradable”, it will be non-toxic, it will break down in home compost bins, and / or it will break down quickly.

But this isn’t necessarily the case.

The good news is, if a product is truly biodegradable, the company should be able to provide details supporting this claim.

And by details, I mean scientific evidence. Not anecdotal claims by the company CEO that they put it in their home compost bin and it “disappeared”.

Real data, based on actual laboratory tests.

Biodegradable Standards: What They Are and What They Mean
Because there are no defined understanding around what “biodegradability” means, certification schemes have been developed based on scientific standards and testing.

Certification is a way for companies to back up the claims they make about the biodegradability of their packaging and/or their products with scientific data.

Whilst voluntary, these schemes are attractive to companies wanting to demonstrate environmental responsibility and safety of their products.

As consumers, knowing that the packaging / product is certified gives us piece of mind, and helps us make better purchasing decisions.

These are the standards to look out for.

Standards for industrial composting and anaerobic digestion:

These standards apply to products that will break down in industrial composting facilities or anaerobic digesters within a stated timeframe. (This is not the same as home composting, and these products may not break down in home compost bins.)

Look out for these numbers stated on the product or packaging:

European Standards EN 13432 / 14995 (13432 applies to packaging only, 14995 applies to plastics generally);

ASTM D6400 is the US standard with clear pass/fail criteria;

The Australian standard AS 4736 which additionally includes an earthworm test;

Japan has no accepted standard, but certification scheme GreenPla is widely used.

Labels proving compostability in industrial facilities are the ABA Compostable Seedling logo, the Vinçotte OK Compost logo, the DIN-Geprüft Industrial Compostable Mark, and the Biodegradable Products Institute (BPI) Compostable logo.

The catch with these products is that not everybody has access to industrial composting facilities. Even when they do, the timeframes required to break down these products (typically 90 days) are often much longer than the timeframes these facilities use per composting cycle. In short, these products may not biodegrade at these facilities and some facilities will not accept them.

Standards for Biodegradable Plastics:

There are a number of different standards for biodegradable plastics, with different certification schemes established by different certification bodies. There is currently no standard with a clear pass/fail criteria for the degradation of plastics in sea water.
Standards for home composting:
These standards are awarded to products that will break down in home composting systems.

Look out for these numbers stated on the product or packaging:

Australian AS 5810 “Biodegradable plastics – biodegradable plastics suitable for home composting”.

Belgian certifier Vinçotte had developed the “OK compost” home certification scheme, requiring at least 90% degradation in 12 months at ambient temperature.

Labels proving home compostability are Vinçotte’s OK Compost Home, the DIN-Geprüft Home Compostable Mark and the Australasian Bioplastics Association (ABA) Home Compostable logo.

“Biodegradable” doesn’t mean there are no heavy metals or toxic chemicals present. Each certification standard has its own permitted levels of metals including copper, nickel, cadmium, lead, mercury, chromium and arsenic: US standard ASTM D6400 has the highest permitted levels.

And if there’s no commercial composting facility in your area, it will likely end up in the bin.

Where possible, it’s always better to avoid packaging altogether.

Is “Biodegradable” Labeling Regulated by Law?

In Australia, the Trade Practices Act (1974) requires businesses to provide consumers with accurate information about goods and services. Businesses that make claims such as biodegradable on their packaging must ensure these claims can be substantiated. It’s the law.

Being able to substantiate claims is particularly important if the claim predict future outcomes, such as whether plastics will biodegrade or within a certain timeframe and under certain conditions.

Claims about biodegradability must:

Be honest and truthful;
Detail the specific part of the product or process referred to by the claim;
Use language the average member of the public can understand;
Explain the significance of the benefit but not overstate it;
Be able to be substantiated.

what is the Application of polylactic acid

what is the Application of polylactic acid?

Polylactic acid has been widely used in biomedical engineering as surgical sutures, bone nails and bone plates. Application of polylactic acid.

The surgical line made of polylactic acid does not need to be disassembled, and can be slowly hydrolyzed to lactic acid and metabolized by the body.

The general degradation time takes six months to two years.

The ideal requirement of a bone plate is that it can be gradually degraded, so that the bone can withstand increasing stress step by step.

The disadvantage is that the mechanical strength properties of pure lactic acid decrease too quickly, so it is generally necessary to add fibers to form a composite material with higher strength.

The application of polylactic acid is now beyond the scope of medicine, and is widely used in some common items.

such as: packaging bags, crop films, textile fibers and cups. Polylactic acid packaging materials were initially costly, but now they have become one of the most common packaging materials.

Through processing such as extrusion, injection molding and stretching, polylactic acid can be made into fibers and films. Polylactic acid film has lower water and air permeability than polystyrene film.

Since water and gas molecules diffuse through the amorphous region of the polymer, the water permeability of the polylactic acid film can be adjusted by adjusting the crystallinity of the polylactic acid.

Poly-L-lactic acid has a low glass transition temperature and can be used in the study of shape memory polymers. Its low glass transition temperature is also used as a feedstock for fused deposition forming 3D printers.

It is also a major component of contouring products. The heat-resistant polylactic acid produced after adding D-lactic acid can be used in microwave heating vessels, containers containing hot liquids and even engineering materials.