Re: Glass

Helen Spiegelman (
Mon, 08 Feb 1999 13:04:24 -0800

Hello, Carolyn:

Thanks for responding so patiently to my little diatribe on glass --

I have very bittersweet feelings about the demise of glass, however I think
-- Anchor Glass notwithstanding -- we may be the last generation to enjoy
the luxury of single-use glass containers.

Have you ever visited the GPI (Glass Packaging Institute) web page:

A few (7!) years ago, I researched glass manufacture and recycling for a
report for our recycling council. What I learned was quite depressing.

1. Glass manufacture is very centralized
Even though sand (the main raw material for glass) is abundant (as the GPI
site says), there has been a significant consolidation of glass
manufacturing into fewer and fewer plants. Today there are only 64
container glass plants in the USA, located in 25 states. Here in Canada,
there were only 5 plants the last time I looked. Therefore *transportation
of cullet long distances* adds to the cost of recycling.

2. Glass manufacture is very demanding
Even though glass plants insist they could all use *more* glass, they are
quick to qualify that: the cullet must be free of contaminants and colour
sorted.-- and alas, many communities don't colour separate the glass at the
curb... The cost of curb separation too great. Hence, commingled glass is
sold (for nothing) to construction sites in my region, to be used as
drainage material -- a complete write-off on the energy investment made to
create the glass in the first place.

3. Glass recycling doesn't save (much) energy
The GPI state that "for every 10% cullet used, there is a 2 - 3% energy
savings" -- Since cullet is used in relatively small proportions
(especially in flint / clear containers) the energy savings are
considerably less than the theoretical maximum 20 - 30 percent energy
savings... and then you have to add in the energy cost of beneficiation of
cullet and of shipping the cullet the long haul to one of those distant
furnaces... At the end of the day, why not just use sand...

I also remember the glass plant in Western Canada told me in 1992 that the
use of recycled material increases the risk of "stones" and "seeds"
(imperfections introduced by contaminants in the cullet) -- resulting in
the draining of the furnace and the destruction and disposal of entire
batches of glass containers. (The risk of harm to consumers from glass
with imperfections is unacceptable -- remember the "exploding pop bottles"
from the 1970s?)

For all these reasons, I avoid buying products in glass, and the ones that
are not elegant or interesting enough to hang onto as future collectors'
items, I throw in the garbage. Alas.

At 12:12 PM 2/8/99 -0600, you wrote:
>Don't assume that all areas have ready and cheap access to silica sand.
>I would like to see the data to support your comments. Thanks for
>sharing your thoughts. We need to do more life cycle analysis to
>determine which is better and also remember that not all areas of the
>world are the same. We have Anchor Glass in Minnesota and I don't think
>your analysis would hold here.
>Carolyn Smith
Helen Spiegelman
3570 West 22nd Avenue
Vancouver, British Columbia

604/731-8463 (fax)