Those charged oxygen atoms can harm the lungs. They carry energy and, as it is oxygen, readily participate in lots of biochemical reactions. Those reactions aren't always beneficial. In severe cases, they can amplify the odds of lung and skin cancer. For some, asthma symptoms can be worsened by exposure to life-size amounts of ozone. ... read more
An allergen is any substance that produces an allergic reaction. But that sounds circular. To flesh it out a little not hard science is all that's needed. ... read more
"Ever since there is no cure however for food allergies, avoidance is the best medicine. Nevertheless, symptom relief is possible when accidents occur. Antihistamines are advisable. It's as well product to have on hand an EpiPen or similar device that allows allergy sufferers to inject a little size of ephinephrine during an emergency. This can stave off any serious attack of anaphylaxis."

allergic reactions to ginger - alcohol allergy For those who suffer more excessive allergic reactions, there are more powerful treatments. Those allergens can in addition become airborne. That means that proximity, not just contact, is enough to move the substance close enough to cause problems.