Question: what ingredients are not good for hair?
Answer: Benzene. This is a toluene, which can damage the respiratory system, irritate the skin, and cause developmental damage in fetuses. ... 
Diethanolamine (DEA) Triethanolamine (TEA) ... 
Formaldehyde. ... 
Fragrance. ... 
Isopropyl Alcohol. ... 
Methylisothiazolinone. ... 
Parabens. ... 
Phthalates.