Emergency cone henna,urgent pls advice

Hi all,I applied a product called Naghma Emergency cone henna onto my 7 yr old daughters hand thinking it was some type of regular henna, but later reading that emergency henna or black henna are dangerous with PPD content and potential risks as it is coal tar used for hair dyes and banned in many countries and directly reacts with blood and builds toxins in liver with health issues and allergies that can be seen after weeks or months or years and future use of any dyes or ink or rubber and has also caused blisters or permanent scars on skin.I even applied little amount on my 4 ur old son as he was crying to have a car drawn on his palm too since his sister got drawn on both hands.The smell was so strong chemical while applying but I still continued applying as I didn't think it cud be this harmful and abt the content in it.The color showed up in seconds while I was drawing.Now I am highly worried after reading the facts abt it.Anyone who has had used this before or heard about it pls share your ideas.I read there's no way the reaction can be stopped now more remove the tatoo sooner.