What to do if hair products around people with fragrance allergies?

Control baseline : Besides pouring varathane on the hair of those who use these things and letting it dry, or increasing airway ventilation, getting better baseline control of your airway allergies is the best thing you can do. If you can decrease airway inflammation by (much)better controlling allergies, this, over time, may make airways less sensitive/inflamed. Decreasing the non-specific sensitivity can help.