Matt, I've found the best place to find the correct information on writing a task specific risk assessment form is on the HSE website at
http://www.hse.gov.uk/. There you should find all the information you require, along with templates.
The risk assessment would cover chemicals, and risk to health if any? For chemicals potential risk if any to a person's health and safety. Use the manufactures COSH forms, which you should get from your supplier, or you maybe able to download from the chemical manufacture's website. whose chemicals you use.
Other information would be the cleaning method/system used to clean each specific item. And type of equipment used for cleaning carpets. upholstery, hard surfaces such as tiles, vinyl and marble/stone. Do check out the HSE site though, very helpful.
Regards Phil