The salient points (emphasis mine):
Federal law requires the EPA to conduct safety reviews before allowing new chemical products onto the market. If the agency finds that a substance causes unreasonable risk to health or the environment, the EPA is not allowed to approve it without first finding ways to reduce that risk.
But the agency did not do that in this case. Instead, the EPA decided its scientists were overstating the risks and gave Chevron the go-ahead
Anyone can use Resist bot to write their representatives (ios app or text “resist” to 50409 - it’ll send them a fax iirc).