 Shares of Sotera Health Co. are set to start trading Friday, after the Ohio-based sterilization and lab-testing services providers initial public offering priced at the high end of the expected range. The company said late Thursday that its 46.6 million-share offering priced at 23.00 a share, compared with expectations of between 20 to 23, as the company raised 1.07 billion in the IPO. 