Just because there hasn't been a specific study linking cancer to Rain-X doesn't mean that Rain-X won't give you cancer. How many decades (not years) was it before a direct link was found between smoking and lung cancer? The same "doom and gloom" train of thought was very prevalent in those days too. Everyone who was trying to warn people about the dangers of it were immediately deemed "joykills" or "doom and gloom-ers".
As for Rain-X....why should anyone do a study between it and cancer? It's meant to be applied to your windshield where it will NEVER come into direct contact with your skin. But as soon as you start rubbing it all over your tablet - where it was never intended to be used - you're suddenly going from no skin contact to CONSTANT skin contact.
If you think there's absolutely nothing to worry about, then by all means, continue using it. Oh and while you're at it, you can also slather some mercury on there too. I hear it really brings out the shine.
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