Cellulose Acetate- The dirty truth part 2

The Environment and Biodegradability

By definition, cellulose acetate materials are resistant to all sorts of degradation, including chemical degradation. This means that anything created with cellulose acetate should be at the bottom of your mental list of "biodegradable" things, because these products linger in the environment for long periods of time. (sciencing.com)

So how can companies say that cellulose acetate is “natural because it grows”?  Well, they can't, because it doesn't. As I stated earlier CA is the by-product of the chemical reaction between volatile acids and cellulose which is derived from cultivated woods and cotton bolls. There is nothing natural about it. The companies who claim CA is natural are simply selling the idea that's been sold to them without having done their own research into the claims that are made in regards to CA.  

sirius shades, biodegradable, sustainable sunglasses, wood sunglasses,

Digging further I found out why cellulose acetate is not biodegradable. In order for CA to degrade, the bond between the cellulose and acids must be broken. 

“Initially, the assessments of the biodegradability of CA reached the incorrect conclusion that the polymer is not biodegradable, due to evaluations being performed only with cellulose degrading organisms like fungi. Later the importance of the deacetylation step was shown, when it was learned that acetyl esterase enzymes are common in microorganisms. link.” (springer.com)

To make this easily understandable, cellulose acetate was found to not be degradable on its own. This means that it has to go through a chemical process called deacetylation in order to initiate the separation of cellulose and the acids that were used to create the cellulose acetate. The degradation process is started using titanium dioxide (TiO2) to create surface pitting and break the chemical bonds between the cellulose and acids within the frames; or through the process of enzymatic hydrolysis in which esterase enzymes (enzymes which splits esters into acids and alcohols) are introduced to the CA in order to start the degradation of the plant plastic. Mind you, titanium dioxide is not biodegradable in of itself and is extremely harmful the environment and wildlife. CA can also be degraded through the process of enzymatic hydrolysis in which esterase enzymes (enzymes which splits esters into acids and alcohols) are introduced to the CA in order to start the degradation of the plant plastic. All this proves that cellulose acetate is in fact NOT biodegradable because it is 1. Created through a chemical process making it unnatural. And 2. It is not biodegradable as it must go through chemical processes in order to begin degradation.

These are the major reasons why we steered clear of CA for our frames. We can not escape the need for chemically modified plant plastics for lenses as there are no better options at the moment but we can eliminate the use of it within our frames and that's why we will always use sustainable woods or bamboo.

Next week we'll cover TAC lenses and the alternatives currently available within the eyewear market.

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