October 11, 2020

Nutritional Biochemistry

Topo Chico

Am I going to throw out my current stockpile of Topo Chico?

Read Time 4 minutes

If you know anything about me, you probably know how much I love Topo Chico sparkling water. I offer it to anyone I come into contact with, and it’s a staple in my household. I drink it almost every day. Sometimes even a couple of bottles. I might as well bathe in the stuff. So you can imagine how my ears perked up after hearing about (and then reading) the recent Consumer Reports piece that discussed per- and poly-fluoroalkyl substance (PFAS) test results from 47 bottled waters (including some flat but mostly sparkling). Given my daily consumption habits, I had one question: 

How dangerous is it to drink “normal doses” of, say, 1 to 2 bottles of Topo Chico per day? 

Let’s be clear: it’s hard, if not impossible, to answer this type of question with such data. I will discuss below what I take into consideration—what we know–and how to make sense of the conflicting information from varying toxicity guidelines. My thinking process with respect to how to regulate my sparkling water consumption is not a precise science by any means. It requires some inductive reasoning. But this is often the case with limited information. Consider this a mini-case study.

Let’s take a step back and talk about what acronyms like PFAS, PFOA and PFOS stand for and why concluding what is “safe” and “not safe” is a difficult task. 

PFAS are a synthetic class of chemicals that include perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS). They have been used for industrial purposes in the US since the 1940s. Even though their manufacture has been phased out in the US, they are still present in many imported products. We also know that they remain in the body for a long time (they have a half-life of approximately 4 years). If you ever saw the movie Dark Waters, you saw what a massive infusion of PFAS, specifically PFOA, did to a community of unsuspecting people. Absolutely horrible. But it’s not clear what much, much, much smaller doses mean.

PFOA, also called C8, is an industrial surfactant that is used to manufacture many products such as carpeting and textiles. One study found that there is a “more probable than not” association between PFOA and 6 ailments: kidney cancer, testicular cancer, ulcerative colitis, thyroid disease, hypercholesterolemia, and pregnancy-induced hypertension. But there was a small sample size, many findings were not statistically significant, and there are epidemiologic confounders potentially not accounted for. (For a little primer on the topic of confounders, please refer back to Part IV of our treatise on understanding science, Studying Studies.)

PFOS is a toxin used in stain repellents like Scotchgard. Higher levels have been associated with preeclampsia, thyroid hormone changes, and high cholesterol. In 2009, the Stockholm Convention decided it had seen enough, and moved to include the compound on a list of persistent organic pollutants that should be restricted in production. 

Let’s be clear. There is enough evidence to say that ingesting some amount of PFAS is bad news: the United States Environmental Protection Agency (EPA) has it listed as a contaminant of emerging concern (CAC). But how much is too much? Even if there are detectable amounts of PFAS (measured in parts-per-trillion, or ppt) in our preferred bottled waters, does that mean we shouldn’t drink them? And in what quantities are they safe?  

There are no federal standards for levels of PFOA and PFOS in drinking water. The EPA has issued health advisories but not regulations, per se. It says that the combined amounts for these two compounds should be below 70 ppt, but other agencies like the Agency for Toxic Substances and Disease Registry (ATSDR) submitted regulatory guidelines at far lower levels (3 ppt for PFOA and 2 ppt for PFOS) than the EPA’s limit. Separate guidelines are issued by a few states that have set their own more stringent limits that range from 12 to 20 ppt. The International Bottled Water Association (IBWA) holds that bottled water should have PFAS levels below 5 ppt for any single compound and 10 ppt for more than one. The Table below provides a list of carbonated water products tested by Consumer Reports in which they detected total PFAS over 1 ppt.

Table. A list of total PFAS (PPT units) in carbonated bottled water. (source: consumerreports.org

So where does this leave my Topo Chico and me? Well, the amount of PFAS in Topo Chico is well below the 70 ppt from the EPA health advisory for maximum amounts in drinking and also below the more stringent state standards of 12-20 ppt.  However, it is almost twice the amount of the IBWA standard of 5 ppt. 

With respect to the quality of evidence, many studies that have been done suggest an association between PFAS and human illness but, as noted above, much of the data is not statistically significant or it is based on observational data from small, non-representative populations. Nonetheless, because PFAS remains in the body for very long periods of time and because there is reasonable evidence that exposure is dangerous, I can’t just dismiss the finding because I don’t want it to be true. However, in the absence of a “maximum safe level” how shall I interpret the finding of 9.76 ppt for Topo? This is a classic signal-to-noise problem. Is there a chance drinking Topo Chico causes cancer or kidney disease? Sure, just like there is a chance that drinking tap water or using a cell phone causes cancer. But would the magnitude of that insult even remotely approximate that of, say, cigarettes on lung cancer? Not even close. Why? Because we should have seen it by now, just as it was seen in Parkesburg, West Virginia when DuPont was dumping C8 into water and landfills like it was their job. In this sense, epidemiology is actually at its most helpful when it finds a no- to low-signal, as in this case. Given how long Topo Chico has been around and the ubiquity of it, should there be any negative effect from its “normal” consumption, it is likely to be very, very small. 

But in the final analysis, at least for me, the precautionary principle, coupled with the asymmetry of being wrong, would suggest it wise to err on the side of caution and cut down on my consumption to a few bottles a week (rather than multiple bottles each day). Am I going to throw out my current stockpile of Topo Chico? No, but I will diversify my consumption with another sparkling beverage (I already have a leading candidate).   

The Consumer Reports article did note that Topo Chico (now owned by Coca-Cola) said it would “continue to make improvements to prepare for more stringent standards in the future.” I am hopeful this happens. But until then, a modicum of caution is warranted. The dose always makes the poison, so I’ll reduce my dose until further notice. (And if you’re reading this over at Coca-Cola, please hurry up and clean up the world’s finest sparkling water!)


– Peter

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  1. Was the Topi Chico tested from the plastic bottle version or glass? And would this make a difference, considering that many on the lower list are in cans or glass bottles?

    • This is exactly my question as well. The study doesn’t say what they used unfortunately. Topo Chico in glass bottles is virtually a completely different product than the ones they sell in plastic.

    • It’s not usually going to be coming from the actual container, it is an environmental contamination such as in water they use, and/or from the carbonization process from what I have read. It takes 4 years to clear out of a human body.

    • Do you know the PFA levels in Gerolsteiner? It’s my favourite, but now I am concerned about my overall mineral water consumption is too high. I drink a minimum of a litre a day.

  2. My wife and I enjoy sparkling water every day as well. What are your thoughts on making your own? We use Berkey filtered tap water and a Sodastream machine. Does the CO2 cartridge put any contaminated into the water in the process I wonder?

  3. Could you be making the situation worse by keeping your stockpile and slowly depleting it? Could letting the liquid sit in the bottles for an extended period of time lead to more leaching of PFAS into the liquid?

  4. Completely with you on the approach to analysis and the risk profile. I think given the situation and data we have, the last point becomes the most relevant: can Coca-Cola make changes to reduce levels and create a win for everyone?

  5. What if you make your own bottled water with Soda Stream? Is the contaminant in the water or the bottle?

    • Just bought mine today, the one with glass bottles. Going to squeeze fruit into it, not going to use chemical flavors.

  6. I know people who drink bottled water whenever they are thirsty, which for me would mean perhaps 6 to 8 bottles a day. My biggest concern is the number of bottles that go into waste system, either to be recycled or discarded. What a job it must be to store the empties, transport them, and dispose or reuse them; multiply that number by thousands of people and we have a gigantic problem. I’ve been buying a liquid mineral supplement; I put a small amount in my water to make my own mineral water. However, I don’t know which trace mineral product is best; do you have any suggestions about what to look for?

    • I have been using Zero water filter pitcher, you can measure it with a meter that comes with it, and taste when it it’s ready to be changed. I have several “Pogo BPA-Free Plastic Water Bottle with Chug Lid, 32 oz.” that I use. Fill up 4 in the PM before bed, you have enough water to last the next day!

  7. I bought a sodastream today (the one with glass bottles), going to use cold filtered water and a squeeze of real grapefruit wedge or other raw juice. I’m not messing around anymore.

  8. As many before my comment has said, are those numbers from glass bottles or plastic?

    If you are looking for a substitute, Gerolsteiner is the best sparkling water in the world. I wish I could get it easily in Australia where I live now. I miss it.

  9. I note the number of commenters who favour SodaStream. Indeed, that does cut out extraneous used containers and waste thereof, uses inexpensive filtered municipal domestic tap water and is less dependant on energy spent on transportation.

    I thought the same, but thought I could improve on the price of SodaStream CO2 canisters. I went down to Calgary Welding Supplies and bought a 20 pound tank of CO2 (the CO2 was 20 lb, but the tank is really heavy). I bought a pressure step-down valve from a local beer making store, and bought various pressure hoses and clamps from Canadian Tire and put together a very satisfactory do-it-yourself carbonization system re-using an old 2 litre (or whatever size) pop bottle.

    The up-front capital cost (for the tank itself) was a little high, but I did this about 4 or 5 years ago and I seem to be still using my original charge of 20 pounds of CO2 satisfactorily, which in theory cost me (Canadian) $25, and the resulting net satisfaction level is considerable.

  10. I should note that I re-use plastic pop bottles. I did consider the option of using glass pop bottles, but the risk of unseen defects in the used glass bottles and explosions during 45 psi CO2 pressurization was a deal-breaker.

  11. Thank you for a balanced assessment on the topic. I’ve read too much about the Coca-Cola Corporation to knowingly buy any of their products. That, in combination with the test results, means there are better solutions than Topo Chico. Aside from already owning it, why do you want to keep drinking it? Is it that the taste is like nothing else available? …or, do you feel a connection with the brand that’s hard to let go of? Having read your work, I know you are better than a brand owned by a company that’s (knowingly) a leading cause of obesity in our country, including children. It’s one thing to offer food that has been shown to be detrimental to health but it’s another to promote or create bad science supporting biased results as well as donating to the most vulnerable underserved groups in our country, continuing an invisible form of suppression.

  12. I wrote to Topo Chico about the PFAS issue. Below is Topo Chico’s prompt reply.

    Dear Michael,

    Thank you for contacting Topo Chico!

    The safety and quality of our products are our top priority. We recently completed an upgrade of our filtration system and lines to ensure the continued safety and quality of Topo Chico into the future. Our own more recent sampling of the Topo Chico product in May of 2020 was below EPA’s method detection limit of 2.0 PPT.

    While our products tested below all drinking water limits for PFAS and other criteria currently set by U.S. federal and state regulatory agencies, we continue to make improvements to prepare for more stringent standards in the future.

    Should you have additional questions or comments, please feel free to contact us again.

    Consumer Interaction Center
    Topo Chico

  13. I’ve found the replacement! 1877 from HEB. It is their attempt to compete with Topo in the Texas market and they nailed it. Water from Mineral Wells, TX, same level of carbonation and same glass bottles. My new addiction.

  14. I’m totally on the Topo Chico train myself. Was introduced to this fabulous stuff about two years ago and became pretty obsessed. I would love to know of any other quality options and IF Coca Cola does “clean” it up soon.

  15. Good article, Peter. One possible minor correction though:

    “However, [Topo Chico has] almost twice the amount of the IBWA standard of 5 ppt. ”

    You previously note the IBWA standard is 5 for any given compound and 10 for total PFAS, so perhaps the better comparison is Topo Chico’s 9.76 versus 10.

    On a more personal note, however, thank you for alerting me to the existence of Topo Chico through your podcast — it is indeed quite excellent.

  16. The larger issue is that it is entirely unconscionable for any bottled water to have detectable PFAs (eg 2 ppt) at this point. Yes, there is much uncertainty, but perhaps as non-specialists we should look to Linda Birnbaum (former Director of the National Institute of Environmental Health Sciences) for guidance — she strongly believes that PFAS should be regulated, as a class, as a hazardous substance, and that safe levels of some compounds are likely below 1 ppt.
    The fact of the matter is that today it is entirely possible to remove PFAS to non-detect levels — San Diego is doing this even with their municipal wastewater. An advantage of this is that it would also remove other contaminants of emerging concern — and if PFAS is present at such levels, there may well be many other unregulated nasties.
    Now, would I drink an existing stockpile? That’s another question altogether. Risk is very difficult to assess on a personal level. But I wouldn’t buy more until they get a grip on this. And by the way, the new science based maximum standards for drinking water in Michigan are at 8 ppt, so it looks like this bottled water would now trigger regulatory action if it came out of your tap there.


  17. Hi Peter – did you see this article? https://www.consumerreports.org/bottled-water/topo-chico-cuts-pfas-levels-by-more-than-half/

    “Topo Chico Cuts PFAS Levels by More Than Half in New Tests by Consumer Reports”

    As CR routinely does when it learns a company has made a significant change to its product, we purchased and tested three new samples of Topo Chico Mineral Water and found that the brand had reduced its average level of PFAS to 3.9 ppt.

    3.9 pretty good!!

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