10 Jan
2006
10 Jan
'06
10:07 a.m.
On 1/10/2006 at 12:09 PM Laurence Cuffe wrote:
Dish washer detergents have changed considerably over
the past fifteen
years in response to concerns about the eutrification of waterways as a
results of detergent contamination. This has resulted in a very
dramatic drop in the phosphate content.
To be sure, phosphate is no longer a primary content, but a quick perusal
of MSDS for some common brands used in the USA discloses that sodium
carbonate or sodium perborate (borax) seems to be used as a
substitute--along with the legal limit of phosphate. The chemistry is
basically the same--sodium carbonate hydrolysis in the presence of very hot
water results in a very basic solution. Said solution will attack
aluminum, zinc and magnesium quite readily--as well as saponify grease.
I would believe that basic chemistry would have changed if detergents used
in automatic dishwashers no longer required very hot water, but that
doesn't seem to be the case. At least I'm aware of no dishwasher detergent
that allows use of cold water.
If you're in doubt about any preparation, it's always a good idea to
consult the MSDS. Manufacturers are required to make it available to the
public by law. Quite often, you'll be surprised at what you find.
Cheers,
Chuck