The Environmental Working Group (EWG) is a lifeline when you start to delve into the clean beauty world. It is a nonprofit organisation comprised of scientists, policy experts, lawyers, communication experts, and programmers who all want to make the world a safer place for us. It researches, studies, and tests food and cosmetics to check for toxic ingredients and then shares the results online and in its app. The skin-deep section of the website is dedicated to all things beauty. It has a database of over 80,000 products currently in its system. The team rates each product solely based on ingredients and breaks down what every chemical in all the products mean. Use EWG to go through all the beauty items you own — you can check what rating they get and choose whether you feel comfortable or not using them after learning about what they consist of. You want to aim for most of your products to score between 1 and 2.
Think Dirty is another resource similar to EWG. It's an app and really simple to work — you can even scan products with it when you're out shopping to check ingredients before you buy them.