When you don't smell it anymore is when you should be
Sour gas contains hydrogen sulfide. It resembles rotten eggs, but at concentrations above fifty parts per million (50 ppm) we lose our sense of smell within fifteen minutes. Above 200 ppm, we risk developing "irreversible pulmonary oedema" – our lungs fill with fluid – and at higher levels death is certain.
insecure mask –
the hiss of vaseline
from my beard
We are driving north and have just passed Artesia, in New Mexico. The last hour has been one of peace. Car windows down, we have savored the heady smell of gas, leaked from the many wellheads adjacent to the road. But we are about to leave the Permian Basin, and already the air is strangely sweet.
Roswell gas stop sign: