I have been in the coolant business for more than 30 years so in general I believe that machining wet is best but having said that a lot of Al is cut dry.
It is typically done at very high SFPM using diamond tooling and don't skimp on the quality as the quality of the tools will translated directly into the surface finish and residual stress in the finished part.
If there isn't some over whelming reason to run dry you would be a lot better off with a good high performance coolant with the appropriate EP additive package to control built up edge it will give you better machining performance with conventional tools e.g. taps etc. and make chip handling much easier.
The H&S arguments about wet and dry are largely academic. if you run wet there is the possibility of coolant mist and if you run dry you will find all the gasses that are found in a welding booth.