Did 3M Know? PFAS, C8, and the Hidden Risks to Brain Development

Published: May 16, 2025
By: Common Joe

I recently watched a documentary on PFAS — the so-called "forever chemicals" — and it got me thinking: could these synthetic compounds be linked to the rising rates of autism? It's not a wild idea. In fact, buried deep in corporate files and declassified documents, there's a pattern of concern that might support this connection — and it's time more people knew about it.

What Are PFAS and C8?

PFAS (Per- and polyfluoroalkyl substances) are synthetic chemicals used in Teflon, firefighting foam, fast-food wrappers, water-resistant clothing, and countless other household products. One of the most infamous of these is PFOA, or C8, used by companies like DuPont and 3M for decades. These chemicals don’t break down easily in the environment or the human body — hence the term “forever chemicals.”

Health Risks: What We Know

PFAS have been linked to numerous health effects, including:

• Immune system suppression
• Hormonal (especially thyroid) disruption
• Liver damage
• Low birth weight
• Some cancers
• Neurodevelopmental changes

It’s this last one — neurodevelopmental effects — that raises serious red flags for conditions like autism spectrum disorder (ASD).

What 3M Knew — and When

Animal Studies

• Lab rats and monkeys exposed to PFOS/PFOA showed altered brain development, lower birth weights, and behavioral changes.
• Offspring had delayed reflexes and reduced brain weights — signs that point toward neurological disruption.

Internal Memos

A 1998 internal 3M memo stated:

“There is a potential risk to children and developing fetuses based on the retention of [PFOS/C8] in human tissue.”

They knew it built up in our bodies. They knew it crossed the placenta. And yet, they didn’t tell the public.

EPA and Public Pressure

In 2001, under mounting pressure, 3M was fined by the EPA for failing to disclose toxicological data — including developmental impacts — from their internal research. One of the key findings? Suppressed immune function and thyroid hormone interference, both closely associated with healthy brain development.

Could PFAS Be Linked to Autism?

While no study — not even from 3M — has definitively declared a causal link between PFAS and autism, modern research suggests a possible connection. Consider:

• Thyroid Disruption: Thyroid hormones are essential for brain development, especially in utero. PFAS interferes with this system.
• Immune Dysregulation: PFAS alters immune responses, and chronic inflammation has been increasingly tied to autism spectrum disorder.
• Prenatal Exposure Studies: Researchers in Sweden, the U.S., and Spain have reported that higher maternal PFAS levels correlate with reduced cognitive scores and altered behavior in children — traits that overlap with ASD symptoms.

PFAS may not cause autism directly, but they could very well act as environmental triggers in genetically predisposed individuals. And if companies like 3M had this information decades ago, their silence becomes more than negligence — it borders on moral failure.

The Bottom Line

If you’re asking whether 3M knew PFAS could disrupt brain development — the answer is yes. If you’re asking whether that could contribute to rising neurodevelopmental conditions like autism — the answer is, we don’t know for sure, but the possibility is real and disturbing.

And now, the public deserves to know the truth.

References

• Grandjean, P., & Budtz-Jørgensen, E. (2013). Immunotoxicity of perfluorinated alkylates: modeling of developmental neurotoxicity. Environmental Health Perspectives, 121(2), 135–140.
• Gump, B. B., et al. (2011). Behavioral and cognitive effects of prenatal exposure to perfluorinated compounds. Neurotoxicology and Teratology, 33(4), 563–571.
• Lopez-Espinosa, M. J., et al. (2016). Exposure to PFAS and children's cognitive function. Environmental Research, 149, 351–358.
• U.S. Environmental Protection Agency. (2001). Consent Agreement and Final Order with 3M Corporation under TSCA Section 8(e).
• Bilott, R. (2019). Exposure: Poisoned Water, Corporate Greed, and One Lawyer’s Twenty-Year Battle Against DuPont.