Is canned food good, evil or somewhere in between in terms of environmental impact?

When I head into the outback, I tend to eat a lot of canned food as I'm still not quite set up properly out there yet to start on my dream - an heirloom and heritage seed based veggie patch, chicken coop etc.

By the end of my stay, there's quite a pile of cans. These can be recycled, but just because something can be recycled doesn't necessarily make it earth friendly or even relatively benign.

So in my current increased consumption of canned food I being an environmental terrorist or on the scale of eco-sins is it more a minor infraction?

Tin cans were originally made from.. tin. Surprising huh? These days they are made from tinplate steel or aluminium. One of the positive advancements in canning technology over the decade has been thinner gauge metal being used.

When I was a wee lad, beverage cans couldn't be crushed by hand and even if you jumped on the suckers, you were liable to do yourself an injury as the steel was so thick. Beverage cans today weigh 40% less than they did 30 years ago, so that means 40% less materials, crude oil and energy goes into the production of today's cans.

But regardless of how thin the steel or aluminium is, the raw materials still need to be mined and processed. The good news is through the simple act of recycling an aluminium can, it's a tiny 5% of the energy it would take to create a new can. In the case of steel cans, the energy saving is 62 - 74%.

According to the Association of European Producers of Steel for Packaging, the multiple recycling of one tonne of steel  allows for the production of up to 6.5 tonnes of steel with the same quantity of primary raw materials. Over 20 cycles, 9 tonnes of CO2 emissions can be avoided. It's not quite closed loop production, but getting there. The Aluminium Association states recycling one aluminum can saves enough energy to keep a 100-watt bulb burning for almost four hours!

The energy savings in recycling cans are certainly well worth the small amount of effort it takes to throw them in the right bin

But what about the whole box and dice - the food and the can? While nothing can be as earth friendly as growing your own food organically, back in 2005,  Dutch environment and food institute TNO, reported that food packaged in steel cans is right up there eco-efficiency-wise and has a high sustainability factor when compared with other packaging options.

In addition, the nutrition levels of canned foods can also be better. For example, canned fruit may not be the cream of the crop; often it's made with bruised fruit that's a little rough - but it's often canned fresher than what we buy "fresh" in supermarkets.

I was watching a news report the other night showing that some of the loose fruit we purchase can be months old! The transportation and storage techniques that allow "fresh" fruit to be kept for so long are big energy suckers. Once food is canned, that's it - no special storage needed and it can last for years.

Canned food can also be cheaper - I know this to be the case with fruit.

A word of warning though, check where the food item was sourced; especially with seafood - some aquaculture farms have their stock swimming in what could be best described as a highly toxic, hormone and antibiotic ladened soup due to lax government and industry oversight, or the fish may be unsustainably and irresponsibly harvested. For example, look for tuna that's been certified as being "dolphin safe".

One other possible nasty of canned food is the lining between the metal and the food itself (if a lining present). Depending on the product, this may be made of plastic which might contain bisphenol A (BPA). This compound is creating a lot of concern in terms of human and environmental impact.

According to the Environmental Working Group bisphenol A is at unsafe levels in one of every 10 servings of canned foods  and one of every 3 cans of infant formula in the USA. Given the controversy that's erupted over bisphenol A, some governments are banning it and companies are scrambling to get it out of their products because of the scare it's causing.

That aside and generally speaking; it seems that canned food may not be as much of an eco-evil as I had previously assumed - but the key is definitely to ensure I recycle the packaging!