Sad story, condoleances.
Still not know what happend?
We know he died of respiratory failure. That is the official statement of the authorities.
I have some possible causes in mind, and I doubt regular refining he did caused this rather unexpected and quick outcome. Me, as well as he, unfortunately experienced accidents involving breathing chemical vapors, usually NOx and chlorine gasses. We were both chemists, professionals, graduated, working with harmful stuff in proper fumehoods... I experienced breathing in NOx fumes, it was bad, it hurt, last for week or two if it was more than just slight whif. I do not say it is impossible to wreck your lungs with NOx outgas, but it would be very unlikely scenario regarding our knowledge and simple fact, breathing AR outgas is immediately unbearable. It must have been something unnoticed immediately.
That is why we do not have any unventilated work benches in my workplace anymore. All chemistry is done in hoods. And it should be this way everywhere. And for any case, certified gas mask ready to use, hanging on the wall, and everybody trained to use it immediately if needed.
