This article is originally published in The Philippine Star:
Guidote, A.M. (2022). ‘Killer’ alcohol. The Philippine Star. https://www.stii.dost.gov.ph/images/jdownloads/pdf_files/sntposts/3Q-2022_STPost_8_as_of_Dec28.pdf
Deaths due to methanol poisoning associated with consumption of lambanog has been a perennial problem. This was again in mainstream news reports in 2018 and 2019. The lambanog contained lethal amounts of methanol. In FDA advisory number 2020-1299, “acute and chronic exposure of humans to methanol by inhalation or ingestion may result in visual disturbances, such as blurred or dimness of vision, leading to blindness and neurological damage, specifically permanent motor dysfunction.”
Methanol poisoning, even as low as consuming 15 mL, can cause death. The symptoms start as headaches and weakness of the body. Some would have dizziness and nausea resulting in vomiting. If left untreated, secondary effects related to vision come in and then death can follow through respiratory failure.
The mechanism underneath this is the conversion of methanol to formaldehyde and subsequently to formic acid. The formate anion from formic acid is responsible for inhibiting an oxidase enzyme, ultimately resulting in lack of oxygen at the cellular level.
The traditional production of lambanog involves distillation that removes the small amounts of naturally produced methanol from the fermentation of tuba or coconut sap. This lambanog is safe and has been consumed by Filipinos for hundreds of years.
The documentary “Patay sa Tagay” of i-Witness mentions that pure lambanog costs P350 per gallon and there is also lambanog that is produced by mixing chemicals and that costs only P150 per gallon. Many buy this because it is cheaper. This most probably utilized denatured alcohol, which is ethyl alcohol with deliberately added methanol so that it is not fit for drinking. It is interesting to note that there is a very large tax imposed on distilled ethanol for drinking versus denatured alcohol.
Methanol, however, can be present not only in lambanog or other alcoholic drinks but also in other products. During this time of the COVID-19 pandemic, there is ubiquitous use of alcohols as disinfectants. It is used in homes, offices, malls, supermarkets, restaurants, government offices, etc. Many even bring a small personal alcohol container for use after every transaction or interaction with others.
Unfortunately, alcohol disinfectants including hand sanitizers can contain the deadly methanol in amounts that are over the maximum limit. At times, it is present in very shocking concentrations. In one test result, a product claiming 70 percent ethyl alcohol instead contained 70 percent methanol!
Methanol should not be present in the products. In laboratory terms, it should be lower than the method detection limit. This is usually 100 parts per million or 0.01 percent using gas chromatography.
With disinfectants, responsible manufacturers have their raw materials tested for methanol. They also have their finished products tested per production batch. Greedy manufacturers skip methanol testing as quality and safety assurance steps in order to save on costs and gain the competitive advantage of selling at a lower price. A very cheap ethyl alcohol or isopropyl alcohol price is a loud warning that the product may not be safe. Alarm bells should be triggered.
In order to protect one’s self, one should buy trusted brands. If the brand is new, do some research and see if they provide certificates of analysis from an ISO/IEC 17025 analytical laboratory. Unfortunately, unscrupulous alcohol sellers can present FAKE certificates of analysis. Their brands can even be approved by the Food and Drug Administration (FDA). It is difficult for the public then to easily determine the safe alcohol disinfectant and hand sanitizer brands even if one checks the FDA-registered list.
In order to protect the public from methanol and its ill effects, whether in lambanog, other alcoholic drinks or disinfectants, product monitoring is important and necessary. Manufacturers must be required to test raw materials and finished products and submit results regularly to the FDA. The FDA should verify whether the results are authentic or FAKE. The FDA should also conduct, more often, the random testing of products sold in the market. This will be a heavy additional workload for the FDA and will require a bigger budget because of the need for more personnel and equipment. Fortunately, the FDA has accredited ISO/IEC 17025 laboratories which can assist the FDA in its mandate of protecting public health. With the collaboration of the public, ISO/IEC 17025 laboratories and the FDA, everyone can be safe from the menace of killer methanol.
* * *
Armando M. Guidote Jr. is the Institute Director of the Philippine Institute of Pure and Applied Chemistry (PIPAC) and a professor at the Department of Chemistry, School of Science & Engineering of the Ateneo de Manila University. Email: armando.guidote@pipac.com.ph