Twice this season, I have heard from people that have shrunk their bee suits! It is easily done. Suits need continual washing especially if you are visiting other apiaries and collecting swarms. Swarms particularly deposit a large amount bee poo on suits as they settle into boxes after a shakedown from their cluster. But also, bees swarm for a number of reason and one of those may be disease control. They may be leaving another colony due to disease in the hive. When collecting a swarm, we can not know what disease they may be carrying, so washing suits after swarm collection is important.
Always remove your veil/ hood before washing your suit. Hoods need to be gently hand washed with a very mild product to avoid any tearing in the veil and more importantly, to avoid any loss of black colour in the veil. If the veil begins to lighten in colour it becomes increasingly difficult to see through the veil. Avoid rubbing or scrubbing the veil as this also removes the black colour. Even a dark grey can make it impossible to see details on the frames. Dry the hood in the shade.
Do the zips up in the suit and then wash it in cold water using a scent free washing powder. I wash my suit by itself or with another suit.
Most importantly, dry in a shaded place. Never put them in the dryer as you will discover a smaller suit at the end of the cycle and an expensive replacement will be needed.