I discovered that when meat and dairy products are labeled "certified organic" in Canada, it means more than merely a lack of harmful chemicals used in raising them. Farms that sell certified organic meat and dairy also have to abide by minimum standards for the animals' welfare, including giving them adequate space and fresh air; they're breaking the law otherwise.http://www.tpsgc-pwgsc.gc.ca/cgsb/on_the_net/organic/index-e.html
This is significant to people like me who believe that all plants and animals are sacred and have intrinsic value. Modern farms which supposedly produce most of the products found in grocery stores, called factory farms, consist of raising animals in very enclosed spaces - placing them right next to each other - as well as giving them harmful chemicals, overmilking cows, and various other activities that improve the bottom line but cause suffering to the animals. To (most?) people who believe animals aren't important compared to humans, there's just the health and environmental issues of having harmful chemicals in your food. But for believers in animal rights, supporting factory farms is immoral, and I'm happy to find that by buying certified organic products I can probably avoid doing so.
For vegetables, certified organic primarily means no pesticides or herbicides, which I likewise consider immoral since unnecessary killing is immoral. So I think I'll buy almost exclusively certified organic food from now on.