Well, Joyce, my first remark is exposing DVDs/VHS tapes to sunlight is a 
big mistake, especially in the greenhouse of a plastic case.
"Direct sunlight can harm VHS tapes

One of the most damaging environmental conditions that can degrade the 
longevity of a VHS tape is if it has been stored in direct sunlight. 
Direct sunlight dramatically reduces how long a VHS tape can last."
 From http://www.memoryhub.com/news/how-long-do-vhs-tapes-last/

The same can apply to  optical storage, especially R types.

I'm pretty sure that plastic degradation does not occur with a couple of 
minutes, or even hours, exposure to sunlight through a window which 
blocks UV. Personally, I see no objection to using bioplastics for 
packaging video records of any type and I would not shoot the 'engineer' 
who selected those plastics.

I take on board your point about recycling bioplastics, something that I 
haven't considered. However, I must ask that, if they become a powder at 
the drop of a hat, how can you recycle them?

Best regards,

Brian.

On 03/07/2015 16:01, Joyce Koo wrote:
> I just have to vent: some of my VHS and DVD cover plastic overlay turn
> into dust upon expose to the sunlight.  Who is the engineer to select bio
> degradable plastic as cover overlay should get shot at... dealt with a
> plastic bag that holding my design book last year with similar outcome...
> Hopefully, no body put those stuff (not in the plastic recycle bin that
> eventually went mixed with others) in some of bridge rebar coating or
> something like that... the half baked engineer plus politically
> correctness mentality is really scary.  (don't know what else of those
> friendly materials was into our life - both dvd and vhs are made in
> china... would think vhs would be safe -before friendly caught on
> fashion... but appear to be not the case...).  Try to pick up those small
> crystalline static dust is not fun... it is everywhere...
> on this cheery note, Have a nice weekend.
>                        jk
>
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