Health experts are expressing concerns as they notice an increase in the use of a common preservative – sodium nitrite – in suicides.

In the past, sodium nitrite poisoning deaths and suicides were quite rare. Even as recent as last December, a team of researchers, in a paper describing a case of sodium nitrate poisoning, called it "rare" and said it was "unusual in the forensic setting."

However, there has been an increase in the usage of the common compound in suicides, the Canadian Medical Association Journal (CMAJ) noted in a news release. In Canada's Ontario, there were 28 sodium nitrite poisoning deaths from 1980 to 2020. Most of the deaths happened in just the last two years of that period, and the number could be higher since Canada "doesn't collect comprehensive data about sodium nitrite poisoning."

A similar trend has also been observed in the U.S., with the National Poison Data System recording 47 cases of sodium nitrite poisoning from 2015 to 2020 alone, according to CMAJ. And just this March, a team of researchers noticed an "emerging trend" in sodium nitrite suicides in South Australia.

What is sodium nitrite?

It is a white salt that's commonly used to cure meat. Like sodium nitrate, it is a preservative that's used in processed meat such as hot dogs and bacon. However, if ingested in certain amounts, it may cause methemoglobinemia, a condition wherein "too little" oxygen gets delivered to the cells. In some cases, this can lead to death.

Unfortunately, even though there are legitimate uses of the compound, online forums that detail exactly how to use the compound for suicides have been fueling the recent trend increase, according to CMAJ. Furthermore, it has also become more readily available, for instance, through online platforms.

Some platforms have even banned the sale of the compound in response to the concerns.

Health experts are now urging physicians to look for signs of methemoglobinemia and use the proper antidote – methylene blue – for it. They are also calling for better restrictions on it in marketplaces. In Sri Lanka, for instance, a ban on certain pesticides led to a reduction in suicides, noted the CMAJ.

This may be a bit more complicated in the case of sodium nitrite as the food industry does use it for legitimate reasons. Furthermore, there isn't an exact dosage at which it can become lethal. So, banning its sale in certain amounts may not be as effective.

"It actually can be a very small dose to a very large dose, so it's unpredictable about how lethal it is, and we know it can certainly take lives even at a lower dose," said Dana Saleh of the University of Calgary, Canada.

One way could be to ban sales to individuals while allowing it for businesses, noted the CMAJ. But overall, preventing suicides by placing restrictions on substances such as sodium nitrite isn't quite as easy as banning it completely.

In response to the experts' concerns, a spokesperson for Canada's health department told the CMAJ that "regulatory action is not the appropriate tool to address this issue," citing the "legitimate" uses of sodium nitrite. Instead, its focus is on "mental health and wellness."

If you have thoughts of suicide, confidential help is available for free at the National Suicide Prevention Lifeline. Call 988 or 1-800-273-8255. The line is available 24 hours, every day.