Who gains from saving nature
Ledger 1 : 33 — For each dollar financing nature-based solutions in 2023, about $33 financed activities harmful to nature. (UNEP)
Cases / Chemical pollution · United States · 1979–2026

3M PFOS: internal evidence, EPA penalty and Minnesota settlement

Nature's voice · report
No measurement of the harm done to me here is on record.
Did nature suffer? Not measured.
What the record lacks: 4 none on record · 5 insufficient · 1 not measured · 3 disputed · 2 unclear See the gaps

3M sold the fluorochemical PFOS until 2000. Internal studies from the 1970s found it more toxic than expected; the company told the EPA in 1998 that it had found PFOS in blood but no adverse effects in workers. An EPA charge closed in 2006 with a $1.5 million payment, and Minnesota settled for $850 million in 2018.

$1.5 million vs $1.3 billion a yearEPA penalty in 2006 vs 3M's direct PFAS sales in 2022
Different years; shown for scale, not as a ratio. The Minnesota settlement of 2018 was $850 million.

Status As of October 2026: the Minnesota settlement and the water-systems settlement are in place; the EPA proposed on 20 May 2026 to rescind some PFAS drinking-water standards and extend deadlines, with no final rule; AIG's coverage suit against 3M (filed October 2024) is the latest dated dispute.

What?
3M's sale of PFOS until 2000, internal evidence of its toxicity from the 1970s, a 1998 notice to the EPA, a $1.5 million EPA payment in 2006 and an $850 million Minnesota settlement in 2018. ProPublica / The New Yorker
Where?
Minnesota, United States; courts in Minnesota and Ohio; EPA. ProPublica / The New Yorker
When?
Internal studies in the 1970s; notice to the EPA in May 1998; withdrawal in 2000; EPA charge closed 2006; Minnesota settlement February 2018. ProPublica / The New Yorker
Who?
Gained
  • 3M — Sold PFOS until 2000; direct PFAS sales were $1.3 billion a year in 2022.
  • 3M — Acquired CUNO, a drinking-water filter maker, in 2005 for $1.35 billion; the unit was later sold through Solventum to Thermo Fisher for $4.1 billion in 2025.
Lost
  • Public water systems and their customers — Carry treatment costs; AWWA estimated PFOA and PFOS treatment at more than $3.8 billion a year in March 2023. Roll Call
Harmed
Why?
the sources reviewed that TSCA section 8(e) leaves it to the company to decide what counts as a substantial risk to report. ProPublica / The New Yorker
How?
The company reported PFOS in blood in 1998 without the animal studies; the Minnesota suit made its internal documents public. Minnesota Reformer (secondary republication of ProPublica)
In proportion The 2006 EPA payment of $1.5 million is about 0.1% of one year's direct PFAS sales (2022: $1.3 billion); the years differ, so this is shown for scale only (calculation).
6 of 6 questions answered from the record

What happened

The record, in order.

PFOS (perfluorooctane sulfonic acid) is a member of the PFAS family of long-lived synthetic chemicals; 3M made it. According to a May 2024 ProPublica and New Yorker investigation, rats given 10 milligrams per kilogram of PFOS a day in the late 1970s died at a rate of one half, and a dose of 4.5 milligrams killed a monkey within weeks. A 1979 internal report found PFOS more toxic than expected. A toxicologist consulted by 3M asked that the substance be looked for in humans; the request did not enter the meeting notes.

In 1997 a 3M chemist found PFOS in every blood-bank sample tested. The only samples without it came from before 3M began selling the chemical or from rural China. Executives blamed the measuring instrument; the chemist's work was restricted after a 1999 presentation to the then-CEO. In May 1998 3M told the EPA that PFOS had been found in blood but that no adverse effects had been seen in workers; the notice did not mention the 1970s animal studies.

3M withdrew its PFOS products in 2000 under pressure from the EPA. It described the blood-bank finding as a complete surprise, and its medical director said the substance was not and would not be a health problem. An EPA charge under the Toxic Substances Control Act (TSCA), the law under which the company decides first what counts as a substantial risk, closed in 2006 with a $1.5 million payment and no admission of guilt.

The Minnesota attorney general sued 3M in 2010. The case settled in February 2018 for $850 million, a natural-resource-damages settlement paid as a grant to a water fund, with a pre-tax charge of $897 million. The company's internal documents became public through the case. No insurance link to the settlement is disclosed.

3M's direct PFAS sales were $1.3 billion a year in 2022, and more than 16,000 of its products contained PFAS. In December 2022 it announced that it would stop making PFAS by the end of 2025. A court approved a separate settlement under which 3M will pay public water systems between $10.5 and $12.5 billion through 2036. A binding US drinking-water limit of 4 parts per trillion each for PFOA and PFOS was set in April 2024. In October 2024 the insurer AIG sued 3M over coverage.

  1. 1979Internal 3M report finds PFOS more toxic than expected; the late-1970s animal studies show rats and a monkey dying at the doses given
  2. 1997A 3M chemist finds PFOS in all blood-bank samples tested
  3. 1998May: 3M notifies the EPA of PFOS in blood, saying no adverse effects were seen in workers; the 1970s animal studies are not mentioned
  4. 1999Presentation to the then-CEO; the chemist's work is restricted
  5. 20003M withdraws PFOS products under EPA pressure
  6. 2006EPA's TSCA charge against 3M closes with a $1.5 million payment, without an admission of guilt
  7. 2010Minnesota attorney general sues 3M
  8. 2018February: Minnesota settlement of $850 million; internal documents made public
  9. 2022December: 3M announces it will stop making PFAS by the end of 2025
  10. 202327 November: Sixth Circuit overturns certification of a class of 11.8 million people in Hardwick v. 3M
  11. 202410 April: first binding US limit for PFOA and PFOS, 4 parts per trillion each; late October: AIG sues 3M over PFAS coverage
  12. 202620 May: EPA publishes proposals to rescind some of the standards and extend compliance deadlines; no final rule at the report date

What was said

Claims, in the words of those who made them.

Where accounts differ

Each party's account, side by side, with its source. The record does not settle these points; it shows them.

What did 3M know about PFOS toxicity, and when did it tell the regulator?
Press and investigations
ProPublica and The New Yorker

A 1979 internal report found PFOS more toxic than expected; a consulted toxicologist's request to look for it in humans did not enter the minutes; the 1998 notice to the EPA omitted the 1970s animal studies.

ProPublica / The New Yorker
Company or project
3M

In 2000 its medical director said PFOS was not a health problem and would not be one; the company called the blood-bank finding a complete surprise.

ProPublica / The New Yorker
Government and regulators
US EPA

Closed its TSCA charge in 2006 with a $1.5 million payment and no admission of guilt.

ProPublica / The New Yorker
Could plaintiffs show which company's PFAS was in their blood?
Courts
US Court of Appeals for the Sixth Circuit

Overturned on 27 November 2023 the certification of a class of 11.8 million people in Hardwick v. 3M because the plaintiffs could not show which of ten companies put the PFAS in their blood.

Does 3M's insurance cover PFAS liabilities?
Company or project
AIG

In its suit of late October 2024 it cited policy language 'limiting or barring coverage' for PFAS and pollution.

Fox 9
Company or project
3M

No position recorded in the sources reviewed.

How it looked

What was shown, beside what was recorded.

Shown

  • 3M's medical director said in 2000, when the products were withdrawn, that PFOS was not a health problem and would not become one; the company called the blood finding a complete surprise.
    3M, as reported by ProPublica · ProPublica / The New Yorker
  • 3M announced in December 2022 that it would leave PFAS manufacturing by the end of 2025, presenting the exit within a sustainable-growth framing.
    3M, as described in the sources reviewed

Recorded

  • A 1979 internal report found PFOS more toxic than expected; half the rats given 10 mg/kg a day in the late 1970s died.
    ProPublica / The New Yorker
  • In May 1998 3M reported PFOS in blood to the EPA without mentioning the 1970s animal studies. About 20 years separate the internal warning from this notice, and 26 years separate the notice from the binding drinking-water limit of 2024 (calculation).
    ProPublica / The New Yorker
  • The EPA's TSCA charge against 3M closed in 2006 with $1.5 million and no admission of guilt.
    ProPublica / The New Yorker
  • The Minnesota case brought by the attorney general in 2010 settled in February 2018 for $850 million.
    Minnesota Reformer (secondary republication of ProPublica)
  • 3M's direct PFAS sales were $1.3 billion a year in 2022, with more than 16,000 products containing PFAS.

Who gained

Money that reached nature, beside money that stayed elsewhere.

Reached nature or the ground

$850m
Single settlement; the sources reviewed give no breakdown of what the water fund spent.
Minnesota natural-resource-damages settlement, paid as a grant to a water fund (Feb 2018)$850m
Pre-tax charge in 3M's accounts: $897 million.

Gained elsewhere

$1.5m
Payment to the EPA; shown for comparison, not as money that reached the environment.
EPA TSCA charge closed (2006)$1.5m
3M direct PFAS sales per year, 2022
$1.3bn
Reached the ground
$850m
Gained elsewhere
$1.5m
Currency: USD · Window: 2006–2018. All figures cover the same period. * Estimate built from cited figures.

Responses on record

  • 3M (2000): Its medical director said in 2000 that PFOS was not a health problem and would not be one; the company called the blood-bank finding a complete surprise. · ProPublica / The New Yorker
  • 3M (May 1998): Told the EPA in May 1998 that PFOS was in blood but that no adverse effects had been seen in workers. · ProPublica / The New Yorker
  • 3M (December 2022): Announced in December 2022 that it would stop making PFAS by the end of 2025.
  • US EPA (2006; May 2026): Closed its TSCA charge against 3M in 2006 for $1.5 million without an admission of guilt; on 20 May 2026 published proposals to rescind some PFAS drinking-water standards, calling the standards to be removed unlawfully issued. · BCLP (law firm)

In court and with insurers

Every proceeding and every insurer decision on record.

Lawsuits and rulings

  1. unknown–2006Settled$1.5m Payment; no admission of guilt
    EPA TSCA charge against 3M over PFOS notification
    US Environmental Protection Agency · Regulatory · US EPA → 3M

    The charge concerned 3M's May 1998 notice to the EPA, which reported PFOS in blood but not the 1970s animal studies. It closed in 2006 with $1.5 million and no admission of guilt. ProPublica / The New Yorker

  2. 2010–2018-02Settled$850m Natural-resource-damages settlement, paid as a grant to a water fund
    State of Minnesota v. 3M
    Minnesota (court not specified in the sources reviewed) · Civil · State of Minnesota (attorney general) → 3M

    Settled in February 2018 for $850 million, with a pre-tax charge of $897 million to 3M. The company's internal documents became public through the case. Minnesota Reformer (secondary republication of ProPublica)

  3. unknown–2023Settled$12.5bn Upper bound, payable through 2036; the lower bound is reported as $10.3 billion or $10.5 billion
    Public water systems PFAS settlement (related matter)
    US court (not specified in the sources reviewed) · Class action · US public water systems → 3M

    A court approved a settlement under which 3M pays public water systems through 2036. the sources reviewed give it averages about $1 billion a year, against an American Water Works Association estimate of PFOA and PFOS treatment costs above $3.8 billion a year (March 2023), with customers carrying the difference. CBS Minnesota

  4. unknown–2023-11-27Overturned on appeal
    Hardwick v. 3M (class certification)
    US Court of Appeals for the Sixth Circuit · Class action · Class of 11.8 million people with PFAS in their blood → 3M and nine other companies

    The appeals court overturned the lower court's certification of the class because the plaintiffs could not show which of ten companies had put the PFAS in their blood.

Insurers

  1. 2024In litigation
    AIG → 3M
    Stated reason: Cited policy language 'limiting or barring coverage' for PFAS and pollution.

    AIG sued 3M in late October 2024. Fox 9

  2. 2024No policy found$27m Environmental-only insurance recovery benefit, 2024
    Not named in the sources reviewed → 3M

    3M's FY2024 10-K reports an environmental-only insurance recovery benefit of $27 million. Its Q2 2026 10-Q reports $290 million for the six months in 'the same three categories'; the sources reviewed does not name the categories or the insurers. 3M / SEC EDGAR

What nature saw

Outcomes measured on the ground, and nature's note.

Nature's report opens this page. Below: further outcomes measured on the ground.

Blood-bank samples with PFOS
All
Every sample tested in 1997; PFOS-free samples came only from before 3M's sales or from rural China
Years from internal warning to first notice to the EPA
About 20
From the late-1970s studies to the May 1998 notice
Years from the 1998 notice to a binding drinking-water limit
26
To the April 2024 rule (4 parts per trillion each for PFOA and PFOS)

What we don't know

Undisclosed, unproven, untried: recorded as data.
Court ruling existsUnder standard-setter review

Nature

  • Not measured Harm to nature: The record holds no measurement of harm to nature.

Insurers

  • Unclear Not named in the sources reviewed: no decision on record.

Accounts

  • Disputed What did 3M know about PFOS toxicity, and when did it tell the regulator?
  • Disputed Could plaintiffs show which company's PFAS was in their blood?
  • Disputed Does 3M's insurance cover PFAS liabilities?
  • None on record 3M: No position recorded in the sources reviewed.

Record

  • None on record What the Minnesota water fund has spent the $850 million on: the sources reviewed give no figures.
  • None on record Which Minnesota waters and species the natural-resource-damages settlement covered: the sources reviewed does not describe them.
  • Insufficient Reported but not independently verified: that in 1976 3M knew of high PFOS levels in workers' blood, and that in 1978 all 20 monkeys in a study died, ending it after 20 days (secondary summary).
  • Insufficient Reported but not independently verified: that 3M agreed in 2022 to pay the Flemish government €571 million for PFOS pollution at Zwijndrecht, Belgium, and appealed a related clean-up decree in 2023.
  • Insufficient Reported but not independently verified: that 3M described its 2023 water-system settlement as not an admission of liability.
  • Insufficient Reported but not independently verified: that 3M's exit from PFAS manufacturing was completed at the end of 2025, with product transition continuing.
  • None on record The lower bound of the water-systems settlement: sources give $10.3 billion and $10.5 billion, against an upper bound of $12.5 billion.
  • Insufficient Reported but not independently verified: that EPA announced on 14 May 2025 an intention to extend the PFOA and PFOS compliance date from 2029 to 2031 and rescind four other limits.
  • Unclear Whether any insurance money went to the Minnesota settlement: no insurance link disclosed.

Did the harm stop?

3M withdrew PFOS products in 2000; a binding drinking-water limit for PFOS took effect in 2024, and in 2026 the EPA proposed rescinding some standards and extending compliance deadlines.

Who paid?

3M paid the $1.5 million EPA payment, the $850 million Minnesota settlement and the water-systems settlement; public water systems and their customers carry treatment costs beyond the settlement.

Sources

Voices on record: ✓ Company or project— Government and regulators— Courts✓ Press and investigations— Communities and civil society— Researchers

Company or project

  1. 3M Form 10-K for fiscal 2024
    3M / SEC EDGAR · 2025

Press and investigations

  1. 3M forever chemicals inside story
    ProPublica / The New Yorker · 2024-05-20
  2. Toxic: 3M knew its chemicals were harmful decades ago but didn't tell the public, government
    Minnesota Reformer (secondary republication of ProPublica) · 2022-12-15
  5. 3M PFAS lawsuits: AIG
    Fox 9 · 2024-10

Connected cases

Related matters, and cases linked to this one through the same organisations, with the role each played in both.
Terms used on this page

Institutions

EPA
The US Environmental Protection Agency.
SEC
The US Securities and Exchange Commission, which regulates securities markets and what companies tell investors.

Science and environment

PFOA (C8) and PFAS
PFAS are a large family of human-made chemicals that persist in the environment and the body; PFOA, also called C8, is one of them and was used to make Teflon.

Law and courts

Class action
A single lawsuit brought on behalf of a large group of people with similar claims.