In a big vacuum chamber like the one Safire uses, that is probably regularly opened to change components it would be impossible to get rid of water vapour, which is the often unwanted guest in many high-vacuum systems.
OK, was thinking it may be a plus that's why I mentioned it. One of many factors, if you take reasonant energy transfer catalysis seriously. If they are shocking hydrogen with trace air; water and nitrogen compounds are likely to form?
