I'm sure this is a silly question, but here goes.

I have a recipe for Royal Icing that I got from http://www.cakejournal.com/archives/how-to-flood-cookies-with-royal-icing and it calls for "pasturized" egg whites.
I used this recipe one other time and I'm pretty sure I did not use pasturized egg whites and fortunately no one became ill.

Thankfully (because I'm making cookies for a friends baby shower) it just dawned on me that I should be using pasturized eggs, but I've never even seen them before.
So, my question is; is it really unsafe to use egg whites? The recipe also calls for 1 tsp of lemon juice and my simple mind was whishfully thinking that would some how make the egg whites safe?

I was hoping to make my icing tonight and will not have time to run to the store, so if using the egg whites is unsafe can I use meringue powder and how much?
Here is the exact recipe if that is more helpful:
2 egg whites
2lb PS
1 TSP lemon juice

If you buy the carton of egg whites, I'm pretty sure they're pasturized. I use Wilton's Royal Icing recipe which uses water, meringue powder and powdered sugar.

http://www.wilton.com/recipe/Royal-Icing

If you google wilton royal icing you'll find a link to their egg white royal icing and they say not to use it in direct contact with cake...I guess they expect it to be use only for decoration.

I've used royal for flooding. And yes, it's just more water. I've also used the recipe in Cookie Craft Christmas for piping and flooding. It's almost the same as the Wilton recipe except they add lemon juice or vanilla extract as well for flavouring. I also used their suggestions for tools and went off to Walmart and bought a couple of small squeeze bottles for flooding.

When you buy pasteurized eggs, they have just been basically heated on the outside. It does not cook the egg. What happens is heating the egg to certain temperature kills the bacteria that can cause food borne illnesses.

Most eggs become contaminated when you crack the shell of the egg. The inside of the egg is usually ok until its broke open

I have used unpasteurized eggs for royal icing before and I have had no problems Hope this helps!