Much of the refrigerated produce in grocery stores is transported there (and stored) in waxed cardboard boxes, and because they can't be reused, and they can't be recycled with the rest of the cardboard boxes that retail stores generate, they get tossed in the trash. If you think about how many stores just in your area stock produce that comes in waxed cardboard boxes, and then multiply that out to include your state or region or country, it adds up a huge amount of waste. In fact, it's estimated that about 1.5 million of these waxed boxes end up in landfills everyday, where they may take as long as 50 years to break down.
However, as they say, one person's trash is another person's treasure, and one company that's been taking this "waste" item and turning it into a resource, is CleanFlame. The company uses the waxed cardboard boxes as the feedstock for clean-burning fire logs that are said to produce 86% less creosote, 80% less carbon monoxide, and 30% less particulate matter (compared to wood). In fact, they say that their fire logs are so clean, you can cook over them.
"Our patented manufacturing process uses 100% recycled waxed corrugated box material acquired through partners in our CleanCycle™ closed-loop production process. By re-purposing boxes used largely to ship perishable produce, our aim is to save trees, relieve overburdened landfills and create a totally sustainable and virtuous manufacturing process - one that can be a model for the world." - CleanFlame
Because I heat almost exclusively in the winter with a woodstove, (I have access to plenty of free scrap wood and windfall trees), CleanFlame sent me some of their fire logs to try out for myself, and while I may not be the ideal customer for them (I'm a scrounger and a woodcutter and a frugal type, so I don't tend to buy things I can source myself), I was pleasantly surprised by their product.
The CleanFlame fire logs burn hot (they say each five pound log has a heat value of 13,000 BTUs), and they burn for a long time (about three hours with the damper wide open). I found them to be a bit harder to get started burning than they say on the package, but once they were burning, the fire logs burned evenly unless they were poked or stirred. According to the website, they can be treated as natural wood logs are, with respect to stirring or poking, but in my experience, doing so opens up the material so that more of it is burning, and this results in a much bigger flame and hotter fire.
I tried out the CleanFlame fire logs in my woodstove both by themselves (starting from a cold stove), and by adding one to a bed of coals, and found that while they were easier to get burning by adding one on top of hot coals, they also burned a lot hotter and quicker this way, as the whole log caught fire quickly. The log I burned by itself took longer to catch fire, but ultimately burned longer and more evenly, without a big flame-up. One word of caution for those who may burn these in an open fireplace: if you don't have a secure screen or glass fireplace cover, once the fire logs burn down to a certain point, they start to fall apart and could potentially come out of the fireplace, causing a fire hazard.
Burning wood for heat (or for ambiance) can be a controversial topic in terms of air quality (depending on how clean your stove burns and the quality and dryness of the wood used as fuel), but it seems to me that if you occasionally use a wood fire, then choosing a clean-burning fire log such as the CleanFlame products is one way to do so without adding a lot of smoke-related pollutants to the air. You can find stores near you that stock CleanFlame fire logs through the company's store locator page.
[Disclosure: CleanFlame sent me some free fire logs for review purposes, but all opinions here are mine alone.]