We’ve seen concerns about the safety of Girl Scouts cookies making the rounds in the news. In this post, we explore the claims around toxic cookies.
Top Takeaways:
- Detection ≠ danger: modern testing can detect substances at incredibly tiny levels, but presence alone doesn’t mean harm.
- Dosage matters: a person would need to eat thousands of cookies daily over a lifetime to reach concerning levels for most detected substances.
- Water and food limits differ and using water safety standards for food leads to misleading conclusions.
What claims are trending in the news and on social media?
In December 2024, an organization sent 25 Girl Scout cookie samples to a laboratory for analysis. The laboratory detected trace levels of glyphosate, a commonly used herbicide, along with heavy metals such as arsenic, cadmium, lead, and mercury.
The organization leveraged the report to claim that children were being exposed to toxic levels of contaminants. The alarming nature of these claims quickly gained traction, causing it to trend in the news and across social media.
Is there merit to the claims that the Girl Scout cookies are toxic?
As with anything, the dose makes the poison. In theory, consuming large quantities of these cookies over an extended period could lead to harm, but in reality, the amounts we eat are too small to pose a significant concern for most of the cookies. Let’s break it down.
How many cookies would we need to consume to cause harm?
Using available averages, we estimated how many cookies a child aged 6-11 weighing 31.8 kg (70 lb) would need to consume in a single sitting every day over a lifetime before potential health effects might occur.
- Glyphosate – 73,953 cookies
- Cadmium – 52 cookies
- Mercury – 412 cookies
- Arsenic – 20.4 cookies
- Aluminum – 92.4 cookies
Lead is a little trickier because there is significant variability in the testing data. Most importantly, unlike most regulated compounds, lead lacks a reference dose and instead has an Interim Reference Level (IRL) of 2.2 μg total per day for children, which is not body weight-based.
- Lead (lowest detected lead level) – 194.52 cookies
- Lead (average detected lead level) – 15.3 cookies
- Lead (highest detected lead level) – 4.14 cookies
While these compounds are detectable, a person would need to consume an unrealistically large number of cookies over an extended period to reach levels associated with adverse health effects.
Does the detection of these contaminants mean they are harmful?
The detection of a substance does not mean it poses harm. Modern testing methods are incredibly sensitive and capable of detecting substances at parts per trillion (ppt) or smaller concentrations. The mere presence of glyphosate or heavy metals does not indicate a meaningful health risk.
For example, metals are a natural part of our soil, and plants take up small amounts of metals during the natural growing process. We cannot eliminate all metals and maintain the nutritional density of food; metals, even some heavy metals, play an essential part role in our biological processes.
Furthermore, regulatory agencies like the FDA, EPA, and EFSA set exposure limits based on rigorous scientific evaluations (not a single person’s professional opinion), incorporating substantial safety margins. If the detected levels are far below established safety thresholds, there is no cause for concern, no matter how concerning it may sound in an article.
What is a safety limit?
The concept of safety limits is essential in toxicology. Reference dose levels are defined as the maximal amount of a chemical you can be exposed to each day for a lifetime. Uncertainty factors are often applied to the reference dose to help ensure the safety of more sensitive or at-risk populations, usually 100 times lower or more.
To see an effect, one would typically have to consume 100% of the dose associated with adverse effects every day over a lifetime. The organization’s report fails to acknowledge this fundamental principle, instead implying that any detection equates to toxicity. That is simply not how toxicology works.
Should food safety limits be the same as water safety limits, as the report used?
Water consumption is vastly different from food consumption. People drink liters of water daily, whereas foods like cookies are eaten in much smaller quantities and at less consistent intervals.
Regulatory agencies establish different limits for different exposure pathways:
- Water limits are often in parts per billion (ppb) due to the large daily intake.
- Food limits are often higher because consumption is much lower in volume.
Applying water safety limits to solid foods creates unnecessary alarm and a false sense of risk. A proper risk assessment must use food-specific exposure thresholds, not arbitrary comparisons.
Is the sample size appropriate for drawing conclusions on all of the cookies?
A sample of 25 cookies from three states is too small to represent all Girl Scout cookies nationwide. Variability in ingredient growth and sourcing, manufacturing, and distribution means that a handful of samples without identified sampling procedures cannot accurately reflect a large-scale risk assessment.
Making sweeping claims about the safety of an entire product line based on such a small dataset is misleading at best.
Does the report misrepresent the risk?
Yes, the report misrepresents the risk and follows a known pattern:
- Detect a substance at trace levels.
- Omit context about exposure limits and safety margins.
- Omit context that metals are a natural part of the environment and can’t be completely avoided.
- Apply irrelevant standards (e.g., water limits) to food.
- Use a small, non-representative sample size to create fear.
While vigilance about contaminants is important, this is not how science-based food safety assessments work to determine a product’s overall safety profile.
Are Girl Scout cookies safe for children?
Yes, children can safely enjoy a serving of Girl Scout cookies without any risk of adverse health effects.
Unless a child has a food allergy or a specific health concern, consuming Girl Scout cookies in moderation is perfectly safe.
The good news.
Despite the alarming claims, the actual risk from consuming Girl Scout cookies is negligible, meaning a typical serving poses no health risk. As with all treats, you can safely enjoy them in moderation.
If you have any questions about ingredients or ideas for a blog post, please send us an email or submit your idea to us at go.msu.edu/cris-idea.
Learn more: citations and further readings.
Perro, M., Seneff, S., & Honeycutt, Z. (2024, December 27). Danger in the dough: Unveiling the toxic contaminants in Girl Scout cookies. GMOScience. Retrieved from https://gmoscience.org/2024/12/27/danger-in-the-dough/
Anderson, E., Kaminski, N., & Zagorski, J. (2024, June 10). Everyday toxicology – Exposure. Center for Research on Ingredient Safety. Retrieved from https://cris.msu.edu/news/everyday-toxicology/everyday-toxicology-exposure/
Anderson, E., & Zagorski, J. (2024, June 17). Everyday toxicology – Exposure-based risk assessment. Center for Research on Ingredient Safety. Retrieved from https://cris.msu.edu/news/everyday-toxicology/everyday-toxicology-exposure-based-risk-assessment/
Anderson, E., & Zagorski, J. (2023, March 13). Everyday toxicology – Thresholds overview. Center for Research on Ingredient Safety. Retrieved from https://cris.msu.edu/news/everyday-toxicology/everyday-toxicology-thresholds-overview/
Anderson, E., Kaminski, N., & Zagorski, J. (2024, January 22). Everyday toxicology – Reference dose. Center for Research on Ingredient Safety. Retrieved from https://cris.msu.edu/news/everyday-toxicology/everyday-toxicology-reference-dose/
Center for Research on Ingredient Safety. Metals. Retrieved from https://cris.msu.edu/metals/
