Tea Tree Oil allergy, what to use instead?

[Angelorum]

So I've been making an all-purpose spray cleaner with this recipe http://www.oprah.com/world/Gorgeously-Green-All-Purpose-Spray and we just figured out that the tea tree oil is seriously annoying dh's system.  We had been thinking it was something in our new house, but then he mentioned that he was having more problems after cleaning up a mess with the cleaner.  I had him take a whiff from the oil bottle and 20 seconds later he was having a wheezing/coughing fit. 

Any ideas for what to sub in for the tea tree?  Or maybe an entirely different spray recipe?

[mumkimum]

I think you'd be fine leaving it out and only using the lavender (assuming that hasn't been bothering your dh either - might want to leave out both EO's for a batch, and then add lavender back in perhaps).   But lavender EO has decent cleaning properties on its own.  

It could be the amount of TTO you're using too - 20 drops is a lot for a cleaner, IMO.  I personally would tend to use less (like 4-5 drops per spray bottle) and you could try that after giving his system a break from it if you preferred it.