Someone asked me if there was any science to salt lamps. You know, those pretty lumps of pink rock salt with a light bulb stuck into them. They are usually referred to as ‘Himalayan’ salt lamps, because the mineral-rich salt is mined in Khewra, Pakistan, roughly 300 km from the Himalayas. The characteristic colour is due to an iron oxide content – the same stuff that makes rust look, well, rusty.
Anyway, well done for asking the right question. When you see a product with health claims that’s not medication and isn’t offered to you by a doctor, it’s wise to ask “what does science say about this?”
But first, what do the people who sell salt lamps say about them?
It varies from seller to seller, and that, of course, should be the first red flag. Does aspirin get attributed different health benefits depending on who you ask? Nope.
Still, here are some claims from just one website:
“As soon as the Himalayan Salt Lamps are turned on, they automatically build up negative ions in the air, dropping and filtering dust floating in the air to the floor, leaving clean air for the body to absorb. [..]
The Himalayan Salt Lamp is proven to be useful in alleviating sleep disorders, helps with the sinuses, those that have asthma or lung conditions. That’s because the Himalayan salt is capable of breaking negative ions and converting them into positive and therefore cleanses the air we breathe.”
Wow. Make up your mind, people.
And here are claims from another one:
“Salt lamps make attractive accent lights. Their main attraction, however, is that the heating of the salt reportedly causes the crystal to release negative ions (often called simply ‘ions’).
Negative ions have long been considered healthy; the sea air, mountain air and the air around swiftly running water is high in negative ions. Indoor air, recirculated air, and air around electronic equipment is very low in negative ions.”
As you can tell, someone needs to get their story straight.
Ions are everywhere. They’re a part of the natural world, and the term simply refers to atoms or molecules which have lost or gained some electrons. Table salt is actually an ionic compound, which means that it is comprised of positive sodium ions and negative chloride ions, bound together due to opposing electric charges.
The usual narrative about these lamps seems to be that heating up a chunk of salt releases ions. However, that simply isn’t possible. To break apart the ionic bond between the two chemicals comprising salt, you’d need a far greater energy input than a tiny light bulb can provide. Besides, if that did happen, the salt would emit chlorine gas, and you’d definitely notice that.
If you want to read a more detailed takedown ripping into the claims promoted by salt lamp peddlers, check out this article.
I would just add that the warm glow and natural texture of salt lamps is quite pretty, but that remains the sole reason for getting them. If you want to improve your asthma, do moderate exercise and use appropriate meds. The end.