You are right that Canada has no free trade agreement with those countries. However, most countries in the world, with very few exceptions, are members of the World Trade Organization. The World Trade Organization has a certain number of rules, including compliance with sanitary and phytosanitary standards.
As a result, our relations and the measures that Canada can take to ensure food safety, plant and animal health protection, for example, are governed by the principles set out in the WTO's agreement on sanitary and phytosanitary measures.
Free trade agreements are rarely very specific about the standards to follow—that's more the role of the application principles. Canada, because of its regulatory system and the WTO obligations, must apply those measures for food safety in line with those principles, based on facts and science.