To my own understanding, the use of room or air freshner indoor and even inside our car is not harmful at all. The essence for producing such things is to help neutralize a lot of micro organisms in the air which are harmful to the health. It is however imperative to note that, the air freshner is not suppose to be used under certain conditions like closing everywhere in the room with air coming and going out if the room. Also it is not suppose to be used in the car while the entire widow glasses is wind up without a.c. also by health exception, it is not suppose to be used oftenly by an asthmatic patient and other person with the health related to asthma.
Once the rules are adhered to, I trust to enjoy the fresh atmosphere wwith the room freshner and car freshner.