Anyone interested in the issues surrounding cosmetic labelling as "hypoallergenic" may wish to read this, from the FDA:
http://www.cfsan.fda.gov/~dms/cos-224.html
There is no regulatory standard for cosmetic companies in regards to what can and cannot be labeled as 'hypo-allergenic', nor is scientific testing required for such labels.
While some cosmetic brands are generally known to be gentler on the skin, there is really no such thing as hypo-allergenic, as one can develop an allergy to anything and any time. While there are some chemicals and ingredients in cosmetic items that are fairly inert and have low occurrances of allergic reaction, nothing can be truly hypo-allergenic.
The best thing for someone with allergy issues in relation to cosmetic items, is to consult a dermatologist and an allergy specialist, and attempt to pinpoint specific ingredients to which they react, and then purchase products that do not contain these ingredients.
When shopping for products, if you have or suspect you have an allergy, make your concerns known to the staff working at the store or counter at which you are shopping, and ask for samples of the products in question. Make sure to recieve enough product to do a patch test of at least one square inch on five consecutive days. This doesn't require a large amount of product. Do a patch test for at least 5 consecutive days, and then wait a full week after concluding your patch test, to check for a reaction.
To do a patch test, apply the product in the same manner as you would for normal use,on a 1 inch by 1 inch square on the skin of the inside of your elbow. Allow the product to remain on the skin the normal duration of time for that product, or until a reaction occurrs- whichever comes first. After the removal of the product each day, check for signs of a reaction. Continue to check for signs of a reaction for a full week after you have concluded the patch test, as some reactions do not occurr until after repeated use.
Often dematologists can suggest cosmetic lines and products which other patients with similar situations have used successfully.
In the end, it is better to err in the way of caution than to leap without looking, for the consequences of oversight and carelessness in matters of health can be very dangerous.