1. Only use a skin care manufacturer who has an in house formulations chemist who specializes in skin care manufacturing. 2. Only use a skin care manufacturer who has in house manufacturing and packaging equipment suitable for your skin care formula. 3. Only use a skin care manufacturer w/ an in house QC laboratory which is used to perform microbiological and identification of raw materials, in process and finished goods. 4. Only use a skin care will provide you with a finished goods C of A detailing the physical and microbiological tests performed on of your finished good.