By Patrick Wright, ABC News
Environmental advocacy groups have raised concerns about chemical solvents used in decaf coffee. Photo: Unsplash
If you're a fan of decaf coffee, you might have come across some concerning headlines about chemicals in your morning brew.
Many people are switching to decaf coffee for health reasons and it's a common choice during pregnancy, when people are advised to reduce their caffeine intake.
Many decaf coffee producers use the "European" or "direct" method, which involves steaming green coffee beans before repeatedly rinsing them with a chemical solvent to extract the caffeine.
One of the most common solvents is methylene chloride, an industrial chemical that is also used in paint strippers, adhesives and degreasers.
The Environmental Working Group, a US-based environmental advocacy group, is petitioning the US Food and Drug Administration (FDA) to ban the use of methylene chloride in the production of food and decaf coffee.
Meanwhile, in April, the US Environmental Protection Agency (EPA) banned most but not all industrial uses of methylene chloride after a risk evaluation found the chemical was linked to neurotoxicity and cancer in certain doses.
The agency has also urged consumers not to use products containing methylene chloride that they may have already purchased for paint and coating removal.
However, experts say that you shouldn't be too concerned about drinking decaf, even if these chemicals are used to produce it.
Should you worry about methylene chloride in decaf coffee?
When methylene chloride is used as a solvent for caffeine, only a very small amount of the chemical remains on the beans.
Under Australia's Food Standards Code, the maximum amount of methylene chloride permitted in decaffeinated coffee is two milligrams per kilogram - in other words, two parts per million.
Meanwhile, the US FDA permits a maximum amount of 10 parts per million of methylene chloride in decaffeinated coffee, which is five times the Australian limit.
Oliver Jones, a professor of chemistry at RMIT, says whether a chemical will be toxic depends on the dose and the levels of methylene chloride in decaf coffee shouldn't be a cause for concern.
"There's not really any evidence that the levels of methylene chloride in decaf cause any problems," Jones says.
"It's not about whether it causes cancer or not - it's whether it [causes cancer] at the levels we're exposed to it at."
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Lauren Ball, professor of community health and wellbeing at the University of Queensland, has a similar view.
"[The US FDA's and the Australian Food Standards Code's] view is that there is none or so little solvent remaining that [decaf coffee is] safe for consumption. That's why it's legal," Ball says.
"There's a theoretical risk that we have - but I'm not aware of any case or evidence or data that people are having negative health outcomes or side-effects because of these solvents."
Food Standards Australia New Zealand (FSANZ) says it considers methylene chloride in decaf coffee safe for consumers up to the permitted level of 2mg/kg.
"Levels of substances in the [Australia New Zealand Food Standards Code] are set using the latest available scientific evidence at a level that poses no safety issues for consumers whilst allowing functional use of that substance in food," a spokesperson told the ABC.
"FSANZ has no plans to change permitted levels for methylene chloride, however if any new scientific evidence indicates there is a safety issue for consumers we are able to amend the Code."
Is decaf coffee healthy if you are pregnant?
Many women drink decaf coffee during pregnancy to reduce their caffeine intake and may be particularly cautious about exposure to any chemicals.
"Pregnancy is a time where many mothers are taking extra precautions about what goes into their body," Ball says.
"I would still go back to the point that [decaf] has been declared safe for consumption."
Some decaf coffee is made without the use of solvents, so that is an option for people who would like to completely eliminate exposure to these chemicals.
For example, some producers extract the caffeine from coffee beans without solvents using liquid CO2 or the "Swiss water process".
Decaf is a common choice for people looking to reduce their caffeine intake for health reasons or during pregnancy. Photo: 123rf.com
One challenge for consumers is that decaf coffee labels often don't contain information about the extraction method, Ball says.
She suggests assuming solvents have been used unless the manufacturer says otherwise.
Finally, keep in mind that decaf coffee still contains some caffeine. A 250ml serve of decaf coffee contains between two and six milligrams of caffeine.
If you're pregnant, it's recommended you limit your caffeine intake to 200mg per day. Healthy adults who aren't pregnant are recommended to limit their caffeine intake to 400mg per day - the equivalent of about four espresso shots.
Are there health benefits to drinking decaf coffee?
Studies have linked coffee consumption to health benefits, including lower risks of some diseases, but it's unclear if the effect comes from the beans or something else entirely.
Some studies have found that health benefits are associated with decaf coffee as well.
"[One] study found that even decaf was proving to be more beneficial than not having coffee at all when it comes to avoiding weight gain over the long term," Professor Ball says.
The bottom line is that your cup of decaf is unlikely to be a health risk, despite the concerning headlines, Jones says.
"The dose [of solvents] is very low and we've been drinking decaf coffee for many, many years. I'm pretty sure if it was causing a problem, we would have spotted it by now," he says.
- This story was first published by the ABC