The guidelines are based on the science, not on opinion. It is also important to recognize that they are guidelines based on the science on a national basis. That does not take away from health and safety occupational health-based considerations, for which there is legislation in every jurisdiction; nor does it take away from the importance of an assessment of the situation the worker is in. It does not override or change that. It is based on the science that in most situations a surgical mask is perfectly adequate and appropriate, and in fact is better for dealing with droplet infections.
There are certain conditions where you're generating a large aerosol, where you're in close contact, etc., and where an N95 mask may be more useful. But the reality is that wearing an N95 mask on a constant basis is very difficult. In fact, we now have research suggesting that nurses who are using N95 masks have the same rate of infection as those who are using surgical masks. So it does not actually provide any additional protection in the general situation. You can think of many reasons for that around the appropriate use of surgical masks: they're uncomfortable, they take time, it's difficult to move quickly. As soon as you touch your eye or face you've negated any effect from that.
As far as the washing of hands, appropriate hygiene, and being careful when you're working around patients--not just about H1N1--that requires a local assessment and decision-making by the professionals involved. None of these guidelines take away from that, but they do provide the best science and advice for most situations we will encounter. We're confident about the appropriateness of them. Again, that does not take away from whatever occupational health standards or individual situation decisions that people need to make.