Probably, a lot of people knows this, but I have discovered it recently. Some weeks ago, I mentioned to the forum that I was having problems with the use of brushes in order to remove dust from negatives, since once in a while a brush produces some scratches to the negative. Now, I am blowing the negatives with a hair dryer, without the heating system. It is a very good way to do this job, and much safer.
Henry.