G'day Gerry
Getting off topic here but have done and will continue to do so until convinced otherwise.
If you were to apply that argument you would not be allowed to use Napisan (or similar containing sodium percarbonate) in the washing machine - which, being grey water, would also end up in the septic system.
Have a read here
http://caravanandmotorhomebooks.com/nap ... tic-tanks/
cheers
Jdog

Dump points don't ever seem to have signage telling you what chemicals can be in the waste. They even accept formaldehyde treated waste. The vented cassette system is far more environmentally sound than using preservatives then dumping in the sewer.

Thanks Jdog,
did not realise that Napisan had evolved so much.
regards
Gerry

All good Gerry
Must admit, the earlier active ingredients don't read that good do they
cheers
Jdog

Thanks Jdog,
Very informative article.
Graham