what pump are you using Brian, you could look at switching if it's job critical.
I'm using the Roche insight which is IPX8 and have been on several onshore sites with it and recently did my first trip back offshore again.
The pump is one thing, but there's the test monitor as well, none of which I know of as being IP rated becasue you can't fully seal them if you need to insert the test strip. The one used with the Insight can be fully switched off as can most of them, which minimises the risk.
I'd go back and look at your company policy/procedures on use of non-IP rated equipment on site - can you for example take a gas detector with you and work under a permit to work? What does your site do for other non-rated equipment like construction tools, air compresors, generators, vehicles etc.