If a US grocery item is labeled "Product of Canada", is it subject to the regulations of Canada or the US (or both)?

The US has importation standards that must be met. The exporting country has its own regulations and its own regulatory structure. For instance, some countries have higher standards for exports than for internal use. That is meant to keep their products attractive to foreign buyers.

My impression has always been that Canadian food health and safety standards are higher than American ones. So, food imported from Canada probably already meets FDA standards.

From Agriculture and Agri-Food Canada, “One of the international organizations in which the Government of Canada, including AAFC, participates is the Codex Alimentarius Commission (Codex). Codex is the major international organization for setting standards to protect the health and economic interests of consumers and encourage fair international trade in food.”

From Food Safety Handbook (Schmidt & Rodrick 2003), “Codex standards are frequently stricter than U.S. standards.”

The FDA expects imports to meet US standards: ”... importers of food products intended for introduction into U.S. interstate commerce are responsible for ensuring that the products are safe, sanitary, and labeled according to U.S. requirements.” From the text on that page, it sounds like they don’t bother to check anything unless they already have good reason to suspect that there’s a problem.

It could be subject to the regulations of China… if it is sold in China.

You didn’t say where you had bought it.

Food products in the USA are subject to all marketing, distribution and production laws that apply to domestic US marketers, distributors and producers.

I imagine that any food for export would have to meet standards of the country of origin,(but who knows what kinds of business advantages international food companies work out).

I like buying food products from Switzerland because all the food made there has to conform to their standards that include what the U.S. would call organic, and then some.

Foods sold in America are supposed to meet American standards, but it isn’t necessarily very well regulated. There certainly has been some “poison” coming in from China and probably other countries too. Not that America itself hasn’t produced some below par products also.

American standards.