Pastel chalk toxic?

Someone recently informed me that pastel chalk was toxic and that I should wear a mask when using them? Is this true? Has anyone encountered this issue?

[Stanka Kordic]

Hi Melissa,

Unfortunately, I believe it's true. I'm not sure of the details, but the dust of the chalk can certainly be irritating to your lungs. I used to work withpastel and quit because I couldn't find a way to use it without energetically kicking up the dust. I was always coughing! I do use oil pastels, but not for commissioned work. Some of the pastelists here may have better feedback.

It's really too bad so many of our tools as artists are bad for our health! Take care.