Methylene Chloride Traces in Major Decaf Coffee Brands Found
We applaud the Clean Label Project’s mission to analyse & raise awareness of chemicals in everyday consumer products.
The full Report, and it’s a weighty and extensive analysis, can be found here:
As part of this, Clean Label Project (CLP) analysed dozens of well-known decaffeinated coffee brands to see if Methylene Chloride (a powerful solvent and the active ingredient in paint stripper) was present in these decaf coffee brands.
It is important to note that this was a test on American coffee brands in the United States - not on European coffee brands in Europe.
Methylene chloride or dichloromethane is a colourless liquid chlorinated hydrocarbon. It is often used as a solvent in paint removers, a solvent in the manufacture of pharmaceuticals, and as a degreasing and blowing agent for industrial use.
But what is the Methylene Chloride Process (MCP) of Decaffeination?
[Disclaimer: Decadent Decaf does NOT roast Methylene Chloride Process decaffeinated coffees. We only roast Swiss Water Decaf Coffees, which uses water (zero chemicals] to decaffeinate the coffee beans]
This is still how the vast majority of coffee is decaffeinated globally. When you drink decaffeinated instant coffee, it will almost certainly be decaffeinated using the Methylene Chloride solvent process.
Likewise, if there's no mention of how the coffee was decaffeinated on the packet, again, it's almost certain to be MCP.
The method of solvent decaffeination is as follows:
- First, the coffee beans are treated with steam to draw the caffeine from the inner coffee bean to the outer surface area of the bean.
- Methylene Chloride is applied directly to the beans. As a chemical solvent, MC removes the caffeine.
- Then steam is applied to the coffee beans again to drive out residual solvent.
- Finally, the beans are dried and roasted, which removes any further residues of the chemical solvent.
So, how were the coffee brand samples tested?
CLP used an accredited analytical chemistry laboratory to blind test a large range of decaffeinated roast coffee brands in the USA (not Europe).
The decaf coffee samples were then sampled into tubes and numbered (with the number corresponding to CLP records to keep impartiality).
Now for the “science”…!
The standards and samples were prepared for analysis using the following approach:
- An internal standard solution containing chloroform and fluorobenzene were purchased at a working concentration.
- A stock standard solution of methylene chloride was also purchased at a working concentration.
- The standard stock solution was spiked into 5mL of water at various levels with the internal standard being added at the same level throughout the calibration range.
- The calibration curve was analysed by Gas Chromatography Mass Spectroscopy with Purge and Trap.
- The samples were prepared by adding 0.5grams of ground coffee to a vial, along with 5ml of water, stir bar, and internal standard. The level of quanti‑cation was 50 parts per billion (ppb).
So, what were the results?
It’s best to review the results properly at:
But see a JPEG of the main summary below: