Please bear in mind that hypoallergenic is a marketing term and has no basis in scientific fact. There is no established test to determine if a product is hypoallergenic or not, and as this would require longterm (up to 20 year) side by side product trials, it's never likely to happen.
It is possible to become allergic to hypoallergenic products - however, if the company has formulated the product using lower allergy risk ingredients , then the risk will be lower. But not as low as actually following the manufacturers instructions - avoid skin contact and ensure adequate ventilation.
The first step is always to visit a dermatologist and get a patch test done. In today's NHS, that may require a fair bit of foot stamping to get the GP's referral. This will determine which ingredient(s) make you sensitive.
Armed with this info, you can look for products that don't contain these ingredients. But unless the NT starts to work safely - double gloving, use of correct UV lamp, correct mix ratio for L&P, and has invested in a professional dust / chemical air filter (price between £700 to £1200), then new allergies will develop. If using L&P, take steps to reduce vapours by using a cover on the dapper dish, air tight rubbish bin that is regularly emptied, etc.
If you can't afford a pro air filter, use dust masks from B&Q with the EN 149 rating.
Table top dust filters, from those we have tried or looked at, are a false economy - they may reduce visible dust, but the replacement filters are generally ineffective at significantly reducing invisible dust which will float in the air like pollution, getting worse with each client until you thoroughly ventilate the room (open all doors/windows to have stiff breeze through). It's the invisible dust that can be inhaled deep into the lungs to cause CPOD or asthma. The chemical filters on these are also useless - the minimum requirement stated by the Nail Manufacturers Association in the USA, is 1kg of active carbon (like BBQ charcoal), that is 1" deep. You can't fit this in a table top or table installed filter, it has to be floor standing. There is a reason why many dust filters never state how much dust and vapours they remove.... :-(. So if you decide to purchase an air filter for your salon - the main questions are:
1. What is the weight and depth of the active carbon filter?
2. What percentage of dust and chemical vapours will it remove? Has this been independently tested?
As an additional layer of protection, you can use a barrier cream on your hands, arms and exposed skin areas. This is not a replacement to nitrile gloves which should always be worn. We use, and a number of well known international Educators use, "Gloves in a Bottle" that can be bought cheaply in Superdrug. A little drop goes a long way and it is not tacky. It's also super for dry patches on elbows and also allows cooking smells/stains (i.e. curry, garlic) and dirt to wash right off. In the nail salon setting this should be reapplied every 4 hours due to the repeated hand washing, not the 8 hours recommended on the bottle.
And please - don't blame the products. Allergies in our industry are caused be poor education and folks ignoring advice. The products are harmless if used as directed - unless you are intentionally/unintentionally buying Chinese product that uses high risk ingredients (and yes, there are some shockers out there - buyer beware). So only buy from a reputable company that clearly has enough advanced knowledge to offer products that are safe.