There is nothing I hate more than a science curriculum that states "these experiments are absolutely safe." First, BORING! Second, some science IS dangerous and these kids are old enough to deal with it. The homeschooling curriculums have one hand tied behind their backs because some parents become very hands-off at these more advanced levels so the kids need to be able to do most things on their own and because homes lack some of the essential equipment for chemical experiments like hoods and fire-proof chemical storage.
So when a curriculum spends the introductory paragraph explaining how safe it is, I tend to tune out.