In a few ways. There is the Draize test, where they drip product into rabbits' eyes. There is a skin test where they put the product on animals' bare skins.
They used to shave rabbits for this, but shaving a rabbit throws uncertainty into the experiment: was the irritation caused by the product or by shaving the rabbit? There are genetically engineered hairless animals they use now for this. There are lethal dose tests but they aren't done except for dyes--nothing else has a track record of killing anyone.
None of these tests is necessary anymore because there's a list of ingredients you can use to make safe makeup, and the most important question (whether anyone likes wearing the makeup item) can only be answered by having people wear it.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.