The Oxidata test kit was pioneered by Apex Energetics. We're not sure if they still manufacture it so you may want to give them a call. We did see it available online from a few online stores:
https://www.naturalhealthconsult.com/shop-by-brand/a/738.html
http://www.naturalchoicesforyou.com/store/p1/Free_Radical_Test_Kit.html
We hope that helps.