

Symptoms of [nitrite] poisoning can vary depending on the amount and duration of the exposure. Those with very mild methemoglobinemia might not have any symptoms at all, or might appear a little pale and feel tired. Moderate-to-severe poisoning is associated with cyanosis (blueness of the skin), confusion, loss of consciousness, seizures, abnormal heart rhythms, and death.
It’s it supposed to be special in some way?
Kind of an aside, but I had no idea that concrete ships were a thing. Not ships carrying concrete, but ships made of actual reinforced concrete, like a building: https://www.youtube.com/watch?v=aLYLBPg56TA