On Wed, 14 May 2008 12:26:38 +0200, Martin wrote:

The high temperature of the oil being burnt must be at least 850C for
two seconds.

It won't last that long in the flame but I should imagine the temp will be
well above 850C.

The answer to my question is: It is an offence to burn old engine oil,
except in an incinerator meeting DEFRA and EU requirements.

Probably, that's why I started with the word "Grandma" hopefully to imply
the "nanny state". B-) I don't think DEFRA (Department for Environment,
Food and Rural Affairs) would be at all bothered, the EA (Environment
Agency) on the other hand would be. The EA is directly responsible to
Ministers not via the "enviroment" part of DEFRA.

--
Cheers
Dave.