Are chickens allergic to anything?

[Big Red Barn]

I've been getting my chickens pine shavings from the local co-op, but now I have the option to get them from a woodshop for FREE. Are there any woods that they are allergic to? My friend told me don't use cedar, but at the woodshop no one uses it anyways. I just want to make sure they won't get sick on me
Thanks!

 

[fried green eggs]

Thats great! Most are fine but I wouldn't use Cedar or Walnut.