This cleaner contains Phosphoric Acid, but works wonders. It does not fail to clean any brake dust, tar or road dirt off my alloy wheels and brings them up like new every time. I understand that Autoglym also produce 'Custom Wheel Cleaner' (which is not the same product) and this may be kinder to the environment and you, but I have used "Clean Wheels" without any harm to my hands, or the grass the car stands on whilst I wash it!
I would thoroughly recommend "Clean Wheels", with the usual safety proviso of avoiding contact with your eyes and trying not to get too much of it on your hands ~ I usually wear rubber gloves and use a car brush when cleaning my wheels.
It took the supplier Xpress Co. two goes to send me the correct item, but we got there in the end!