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Additional Information
Roundup® is a widely used weed killer (or
"herbicide"). It is very effective because it kills the
roots, not just the green part. It also sticks to soil particles,
so once in the ground does not affect other plants, and degrades
fairly rapidly.
The method originally used to make Roundup®
involved first making an intermediate, and then converting this
to the product. Unfortunately there are three main concerns associated
with this process:
- Extremely toxic hydrogen cyanide is used
- Cyanide-containing waste is produced
- The reaction is exothermic - it produces heat, which must be
removed
Monsanto, the company that makes Roundup®
has developed, and is now using, a much safer manufacturing route.
It uses a different, much less toxic starting material. The reaction
also takes fewer steps, making it simpler and cheaper.
This table compares the two processes:
| Old process |
New process |
| Uses hydrogen cyanide, which is extremely
toxic - Just 300 parts per million of hydrogen cyanide in air
will kill a person in a few minutes! It is a risk to workers
and to those living nearby |
Starts with a much safer chemical,
and does not use hydrogen cyanide at all. Reaction brought about
using a copper catalyst |
| 1kg of waste is generated for every
7kg of product, and it must be treated to remove toxic cyanide |
It is "zero waste", as
all the starting materials end up in the product. The catalyst
can be used again. |
| The reaction is exothermic (it gets
very hot). If there is a problem and the heat cannot be removed,
a dangerous "runaway reaction" (uncontrollable reaction)
could occur. |
The reaction is endothermic (it gets
colder if it is not heated). There is not possibility of a runaway
reaction. |
The new process is much safer for everyone
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