Is the Apple Watch series 4 aluminium case nickel free?

Hey there!

So i've developed a certain interest towards the apple watch series 4. I think they may very well complement my iPhone but there is one big catch: I am very allergic towards nickel. After doing some research, I discovered that stainless steel is out of the question, since that almost always contains nickel. But I also discovered that some Apple watch series 3 aluminium models contained nickel as well. Has Apple changed this with the new Apple watch series 4? It also tends to differ per color, what versions are safe to wear? I am aware of the existence of Wearing your Apple Watch - Apple Support that page that explains everything, but it is very vague and it basically says that all Apple watches potentially have some nickel and/or acrylates in the case and/or band.

Thank you all very much for reading my question =)