Q. Dear Umbra,

I need to buy new mattresses. Which are environmentally better: foam (100 percent plastic), latex (assuming plant origin, not petrochemical), or horsehair and springs (I’m certain the horses did not surrender their hair willingly)? Please advise!

Caroline F.
United Kingdom

A. Dearest Caroline,

I firmly believe one’s bed should be a true getaway, a peaceful place to escape from the world and lose oneself in happy dreams. It’s no place for worries about toxic chemicals, non-renewable resources, animal cruelty, or king-size environmental footprints. So if you’re in the market for mattresses, choosing the eco-friendliest one you can is a great way to go. Let’s line up the options and give them a good bounce — I don’t want you to lose any sleep over this decision.

Polyurethane foam is very common in the mattress world; it’s found in straight-up foam mattresses, memory foam (aka viscoelastic foam, a high-density polyurethane) mattresses, and sandwiched into innerspring models that also contain nylon, polyester, and steel springs. You note one problem with the stuff already, Caroline — it’s (nonrenewable, petroleum-based) plastic. Another issue with PU foams is that they off-gas volatile organic compounds (VOCs), which loyal readers will recognize as vile chemicals that can cause everything from headaches to cancer.

On top of that, there’s the flame retardant issue. Here in the States, we are customarily offered beds, furniture, and plenty of other household items legally soaked in dangerous chemicals to keep them from going up like torches in the event of a house fire. These chemicals have terrible effects on our health. There has been good news on this front lately: The worst of them have been phased out of production, and new regulations that went into effect last year let furniture makers skip some flame retardants. But older foam mattresses (pre-2007) might have them, and baby mattresses are even more likely to be treated. Doesn’t exactly make for sweet dreams, does it?

For all these reasons, foam mattresses aren’t going to win any green contests. If you do end up with one, letting it air out on a deck or in a garage for several days will reduce the VOC problem. And did you know that it’s possible to obtain a flame retardant-free mattress legally — with a doctor’s note? The things I learn writing this column.

So on to your next suggestion: latex, which can be made synthetically or from the sap of rubber trees. The natural variety is indeed a renewable resource, and it’s flame-resistant by nature, so it often comes without the chemical cocktail (with these, manufacturers can comply with fire-safety laws by including a wool layer — another naturally fire-resistant material). That makes them a better choice, but be aware that most of these mattresses are made from a blend of natural and petro-style latex for durability.

This brings us to the other (bedroom) suite of natural mattress-stuffers: horsehair, wool, and cotton. You don’t hear much about horsehair mattresses (at least, not on this side of the pond) because they’re often extremely expensive — we’re talking $10,000 up to $80,000. In fact, let’s not even get into where the horsehair comes from (OK, slaughterhouses, most likely): If you are even considering buying one of these, I implore you, purchase one of the other two all-natural options instead and donate the rest of that cash to your environmental nonprofit of choice. You’ll sleep better at night, I promise.

May I point you to wool and cotton instead? Wool mattresses are favored among the green set because they’re renewable and, as we discussed, naturally flame-resistant. Go for brands that come from organically raised, humanely treated sheep for extra bona fides (look for California-produced PureGrow Wool). Likewise, cotton mattresses are plant-based (and often get their flame resistance from a wool wrap); go for organic cotton to minimize the impact of synthetic fertilizers and pesticides. The downside of these natural options? They ain’t cheap (though they aren’t horsehair-level extravagant).

No matter which stuffer you choose, look for a quality, durable mattress that will last — the longer its life, the smaller the overall impact of your sleeping habits. And as for the mattresses you’re replacing, Caroline? Do consider finding a recycling facility for them. Many of a mattress’s components can (and should) be made into fresh new items. Then treat yourself to a nap on that new bed. All this comparison shopping can be exhausting.