Sterling silver and titanium contain no nickel, you can shop these here:
https://www.sourcherry.co.uk/collections/sterling-silver
https://www.sourcherry.co.uk/collections/titanium
We have a short blog post about this, if you would like more information: https://www.sourcherry.co.uk/blogs/sour-cherry-blog/lets-talk-about-stainless-steel-925-sterling-silver