Essential oils, used for everything from insect repellents to aromatherapy and fragrance, are very strong and need to be used with care, but they can cause environmental health problems if the brand doesn’t provide pure oils. Some oils have petroleum-based solvents added, which can be very toxic. Petroleum-based solvents are often long-lasting in the environment, are stored in our fat, and are a source of volatile organic chemicals (VOCs) that negatively affect indoor air quality.
Do an easy blotting paper test to see if your oils are pure. Put a few sample drops of your oils on a blotting paper. Pure essential oils will not leave any residue once they have evaporated, whereas petroleum solvents will.