The word "credible" is a loaded, toxic term when it comes to evidence, kind of liked proof by intimidation. If you mean there's no high quality evidence showing harm yet I agree. That doesn't imply safety, as much as industry likes to insinuate. I thought it was all conspiracy too, until I saw enough decent scientists questioning possible mechanisms and asking for more research. The problem is that like pharmaceuticals, it's very hard to get funding for high quality research that would drastically affect an industry. So we're still at a "maybe", but definitely not at the levels conspiracy theorists say. Important not to succumb to black and white thinking.