Nitrous oxide is bad for people and bad for the Earth. We know this. So why is it in every can of whipped cream? Can't we find something else that's just as good? The answer is no. Laughing gas really is the best option, and here's why.
A few years ago, I did a short piece on why laughing gas works so quickly when inhaled. Nitrous oxide consists of two nitrogen atoms attached to an oxygen atom, the latter of which allows the nitrogen atoms to piggyback their way into the blood of the consumer. When people breathe pure nitrogen down into their lungs, it fills the alveoli — the little sacks in the lungs — but it doesn't manage to cross from the alveoli into the bloodstream.
In a pinch, nitrogen could enter the body through fatty tissue, if that bit of pressure. It's this property that makes nitrogen and whipped cream an inseparable pair. When someone sprays a whipped cream out of a can, dissolved gas in the cream bubbles up, turning the cream into a foam the way carbon dioxide bubbles turns soda into a foam when a soda can is opened. The more gas that can be crammed in, the fluffier the whipped cream will be. Oxygen would double the volume of cream, but nitrous oxide quadruples it.
Perhaps the fluffiness alone doesn't account for the popularity of laughing gas in a whipped cream can. After all, the volume of whipped cream alters depending on its fat content and the pressure it's been under. There might be other ways to fluff up milk fat. Companies might even be wise to use oxygen in their cans, as less volume might make people use more product.
But there is the little matter of bacteria. Whipped cream out on a hot day can turn fast. Oxygen encourages the growth of many types of bacteria. Nitrous oxide is as bad for bacteria as it is for us. We let it kill them while we serve it on our slices of pie.
[Sources: Culinary Reactions, What is Laughing Gas Doing In My Whipped Cream, Why Is Nitrious Oxide Used In Whipped Cream]