Pesach Faqs

My cousin has child with a very rare genetic disease which requires her to eat corn starch regularly. Since she is a child and also has a chronic illness, it is clear that she can eat kitnios on Pesach, but we do not want her to be eating chametz. There is a medical preference that she should stick with the brand she is used to, so here is my question: do you know if the Argo or Kingsford brands of pure corn starch, certified year-round by the OU, contain chametz? We contacted the OU, who informed us that those products are produced without any chametz additives, and are suitable for use by anyone who may eat kitnios on Pesach. It is worth verifying this information before each Pesach to make sure nothing has changed in the factory.