Reviewed and rejected: Jonathan and Aesop conditioners
The problem is that there are also too many nasty things to turned a blind eye to. One of which is methylchloroisothiazolinone, a skin and membrane irritant that can only be used in restricted concentrations in rinse-off products. There is also methylisothiazolinone, which was found to be a neurotoxin in a test on rats, an irritant called benhetrimonium chloride and another called butylphenyl methylpropional.
The other conditioner to disappoint was Aesop's. Not only did it do very little for my hair (I was feeling a little desperate, so tried it despite all warning signs), the third most dominant ingredient is stearalkonium chloride, which is actually a fabric conditioner and is toxic and unsafe.