Residual Solvents Testing For Hand Sanitizers…Why Is This Important?
For cleaning your hands, the CDC recommends using an alcohol-based sanitizer with no less than 60% ethanol if soap and water is not accessible. However, there is increased danger in using hand sanitizers that may contain toxic contaminants or byproducts, including methanol (AKA methyl alcohol, wood alcohol) and 1-propanol (AKA 1-propyl alcohol, n-propanol).
The FDA has issued several updates warning consumers about the use of hand sanitizers that may contain methanol or 1-propanol. On August 24, 2020, the FDA provided a modified version of the USP <467> Residual Solvents method that utilizes mass detection (MS) for impurities in hand sanitizers, and sets tentative limits for potentially harmful levels of these impurities. The method is also suitable for assaying the % alcohol content (ethanol and isopropanol) that makes hand sanitizers effective.
What changed in the modified method?
- The total runtime was reduced by increasing the temperature gradient. In turn, impurities are identified based on retention time as well as by matching to the NIST Mass Spectral Library. Using GC-MS instead of GC-FID allows for better separation and increased confidence in identifying these impurities.
- Spike and recovery studies are included in the modified FDA method to increase identification confidence.
- The new method is direct injection only. Density of the hand sanitizer is factored into the calculations.
- In USP <467> Residual Solvents, methanol and 1-propanol are only analyzed if they are LTBP (likely to be present), which means we only include them in the analysis if you specify that you want to test for them. These impurities are assessed using a limit test approach. The modified method can be used to assay percent level ethanol or isopropanol, as well as to detect the listed impurities. Methanol is assessed quantitatively, and 1-propanol is assessed using a limit test approach, but the limit is 5X lower than specified in the original USP <467> Residual Solvents method.
How can I get my hand sanitizer tested?
We are proud to offer testing by this new modified procedure, as well as the original USP <467> method. Please specify “FDA Hand Sanitizer Method” on your GC Analysis Request form if you would like us to test your hand sanitizer samples using the new modified procedure. Be sure to specify ethanol and/or isopropanol if you require an assay for % alcohol in your sample.
If you aren’t sure which method to use, just give us a call and we’ll walk you through the differences and help you choose what’s best for your samples.
Links
- CDC Hand Hygiene Recommendations
- FDA updates on hand sanitizers consumers should not use
- Direct Injection Gas Chromatography Mass Spectrometry Method for the Detection of Listed Impurities in Hand Sanitizers
- RML GC-FID/GC-MS Request Form