I have had a snail mail reply from the Enviroment Agency.
My email question was "I ask you to please provide me with the chemical composition of the liquids permitted to be used in such spraying."
Their reply enclosed documentation relating to one specific product named Mist Air Odour Neutraliser manufactured by Sita.
ASC
This product appears to be a natural and not petrochemically constituted.
It was mentioned in the minutes of a Shropshire council meeting--
"In response to a question raised on behalf of Mr Bodenham, the Waste Management Officer reported that the mist-air odour neutraliser was used extensively in many parts of the world and should not cause any health problems. One of Shropshire Waste Management’s staff suffered with Asthma, but had not had any reaction to the neutraliser. At the request of the Chairman, he undertook to let members have information on the composition of the neutraliser."
The Enviro Agency reply does not specify whether the use of this particular product is compulsory. An posting here indicated that the product used on Whinney Hill smelt like air freshener. Mist Air Odour Neutraliser has only 2 varieties - apple and neutral. This makes me think that a different product is in use at Whinney Hill.
I have Googled a search for probable alternative products that the council might be using, and found these two-
EcoPro Ltd | Services | Odour Control | Landfill which states-
"Alternatively the bad odours can be masked by using a concentrated fragranced product. Dispersed into the air as a fine mist, it provides a cover up of a pleasant fragrance, available in "Apple", "Sea Breeze", "Cut Grass", "Floral", "Wild Herb", "Pear Drop" and "Garden Mint".
I have as yet been unable to find a record of its chemical composition on the web (will have to mail the company). The use of the words 'masked' and 'cover up' have made me suspicious that this is a petrochemically based product.(In contrast the Mist Air product described above works by 'absorption' and can be described as 'air washing')
Another possible product is Air Spectrum-http://www.odour.co.uk/datasheet.asp
Air Spectrum Enviromental Limited
-- which does appear to be non toxic/not petrochemical.
Before this investigation can proceed I need the answers to the following-
1.- Which product does our council use? (I will mail our local waste management)
2.- Is the use of the product Mist Air Odour Neutraliser supposed to be compulsory? (will mail the Enviro Agency who have replied, and happens to be in Preston)