response: It can be dangerous since its concentrated form can be hazardous and caustic.
original_response: And not only do they smell, but they can irritate the skin. Ammonia is very caustic!
history: Hi, Have you ever colored your hair? No but home coloring had almost reached 2 billion in the US in 2011 and was expected to hit 2.2 billion in 2016. Wow that's a lot of money for hair coloring. Can you guess why I did my hair? The main cosmetic reasons for it would be covering gray or white hair, to get a more fashionable color or restoring one's original hair, so would it be one of those? Yes, the last one, I had some issues with my hair coloring and had to get it done to look like my old self again. Do you know who I went to for it? So it can be done at home or done professionally by someone like a hairdresser. Would it be by a hairdresser? Yeah, there was a nasty ammonia smell though, I don't know if it is dangerous or not though.
knowledge: Although common in nature and in wide use, ammonia is both caustic and hazardous in its concentrated form.