Firstly, as a word of caution, making your own products does involve an element of risk. If the product is not completey fresh you will need some sort of preservative. Without this you would likely breed all sorts of fungi or bacteria that could be harmful to the client. A good natural preservative is grapefruit seed oil (and vitamin E to some extent). You should take professional advice on what would work in your recipe. Your containers need to be sterile.
Certification (safety assessement) is required to sell any cosmetic product within the E.U. This procedure costs IRO £200 per product. You also have to adhere to labelling restrictions
You would need to provide the following:
Material Safety Data Sheets.
INCI names for ingredients needed for labelling
Information on your Product Information File. (recipe data).
It is possible to buy pre-certification packages for common products to which you can add a limited amount of specific optional ingredients to create your own personal blends. This costs about £75 and provides all the data required above. You could also go direct to a toxicologist.
Here is a link to the DTI regs in full:
http://www.dti.gov.uk/ccp/topics1/guide/cosmeticsguide.pdf
If you are making a home made gift than this is not required to be certified. Anything that makes money or is for profit (even making for school fairs etc.) DOES not to be certified.
I would urge you to call your insurance company and check out what they need you to do to cover you in the event of a problem. There must be some ways round it, as herbalists and aromatherapists make their own stuff all the time - but I think the insurance company would know.
Hope that helps even if it is not the answer you wanted to hear. Let us know what your insurance company say?
