I have used Aqua Net unscented since my days as a professional dancer when hair had to stay in place during costume changes and much spinning and jumping. Hairspray works by what is known in the cosmetics industry as "spot welding;" junctions of 2 or many more hairs is stuck together with hairspray and this holds the entire style in place. The hair does not need to be saturated as with gel - just misted lightly as though you threw an invisible net over your hair.
Recently I tested hair treated with hairspray (containing alcohol) under a microscope. Because I get the best images with items placed in a liquid, I left the hair in the hairspray. That was a mistake. (Click the photo for a larger image).
Today when I sprayed hairs with hairspray and let them dry, washed them and repeated the process 5 times, I saw no such damage. By then, the hairs were accumulating some residue (my washing wasn't especially thorough) and one spot which had been immersed in hairspray was looking damaged, but the rest was fine. No visible damage - and I can see porosity increases. Yes, I should do that 20 or 50 times to be sure. Maybe if I had a large hank of hair to work with instead of individual strands...
So why do we think this is bad for hair? I have seen people whose hair looks damaged who use hairspray - but is the hairspray to be blamed exclusively? I believe the answer is not entirely in the dehydration of alcohol from hair - a process which could pull water from hair in the process. Alcohol is very effective at removing oils and anything oil-like from hair and skin. This is a major down-side of alcohol in any cosmetic formula. Alcohol is also a solvent which does cause hair to swell, so if hair is too well-cleaned and not protected by emollients (silicones, oils, some conditioning ingredients) in the hairspray or oils from the scalp or conditioners or hair gels, it is especially vulnerable. Lack of a protective emollient coating allows alcohol to contact the hair and the alcohol may damage what little emollient is there. Any time hair swells, there is stress to the hair shaft as a whole. This condition would also encourage dehydration of hair, dullness and loss of elasticity.
©Science-y Hair Blog 2013
My hypothesis
I think the problem is that people often over-use or mis-use hairspray in conjunction with other hair-damaging practices (high-heat tools, teasing/back-combing hair, ordinary brushing, bleaching permanent coloring). But especially hazardous is using too much hairspray in one place, or using it every day! Hairspray needs to be completely dry within 30-45 seconds or it may cause damage. That means your hair should not be well-wetted with hairspray. Thus instructions say, "hold 6-8 inches from hair and spray."
The key seems to be to use hairspray sparingly so it does not take much time to dry and to include emollients in the formula (or on the hair as oils or conditioners) to protect the hair by forming a barrier to the alcohol. Those emollients also reduce the shellac feeling of hairspray.
I think as long as we use hairspray as an "invisible mist-net" to occasionally finish off a style and avoid saturating the hair with it, our hair can remain dazzlingly healthy - and glamorous.
When I used to walk into the high-school ladies room in a cloud of hairspray and 4-6 inch tall bangs/fringe - that was so very wrong.
