Really? I most strongly disagree.It's perfectly safe if you're aware of the risks and are careful about it.
Most all divers that have died with CO have been perfectly aware of the problem
and careful about it yet they died diving unawares due to CO poisoning.
Carbon monoxide poisoning is a well recognised, hazard for divers.
CO poisoning occurs mainly as a result of burning oil only in a oil lubricated breathing air compressor or from external ambient air contamination from a combustion engine exhausts from a nearby petrol or diesel engine and especially from those fitted directly to the breathing air compressor itself.
Such as those fitted to the hopelessly inadequate Coltri MCH 6 and ICON sports divers air compressors.
Further from the medical treatments perspective the incidence of carbon monoxide poisoning is massively under reported as it also manifests itself similar to decompression sickness, and as both conditions are treated with the same medical hyperbaric treatment and tables using hyperbaric oxygen. for used for diver treatment. With the exception for suicide attempts, fire inhalation and other ambient air CO cause contaminations.
Please for the benefit of others reading this thread please re consider your reply.
It's frankly never ever perfectly safe and being careful is patently untrue misleading and a dangerous position to advise to fellow divers in an open divers forum.
A capable calibrated and verified CO detector is at the very least the only form of risk you need to be aware and make to test the contents of your cylinder before you enter the water. Feel free to disagree. Iain