When Are PFOA and PFOS Considered Safe?
The German HBM-Commission sets HBM-I values as conservative benchmark levels in blood plasma below which no adverse health effects are expected:
- 2 ng/mL for PFOA
- 5 ng/mL for PFOS
Staying under these levels generally means current scientific knowledge does not expect harmful effects — the exposure is considered “safe” under existing regulations
What If Levels Exceed Safe Thresholds?
The HBM-Commission also defined HBM-II values, thresholds above which the probability of health risks increases, and further action or monitoring is recommended:
- For women of child-bearing age: 5 ng/mL PFOA or 10 ng/mL PFOS.
- For other population groups: 10 ng/mL PFOA or 20 ng/mL PFOS.
Values between HBM-I and HBM-II are considered a “grey zone” — risk can’t be ruled out, especially over long-term exposure. Once HBM-II is exceeded, there is elevated concern for possible adverse effects.
Why These Thresholds Were Set
Over decades of biomonitoring and epidemiological research, elevated blood levels of PFOA/PFOS have been linked to:
- Reduced fertility, lower birth weight, developmental impacts
- Altered lipid metabolism (e.g. increased cholesterol)
- Impaired immune response, reduced vaccine effectiveness
- Hormonal changes, thyroid disruption, reproductive health concerns
Given the evidence, the HBM-I values were derived as precautionary “safe limits,” while HBM-II reflects levels where health effects may begin
Are Many People Above the Safe Levels?
Studies show that in certain populations — including children and adolescents — a considerable percentage have PFAS levels above safe benchmarks:
- In a German national survey of minors, ≈ 21% exceeded the PFOA HBM-I value, while ≈ 7% had PFOS above HBM-I
- A small portion (0.2%) even exceeded HBM-II thresholds for PFOS
These findings indicate ongoing exposure risks, often linked to contaminated drinking water, environmental pollution, or legacy uses of PFAS-containing products — such as certain firefighting foams.
Monitoring & What “Safe” Really Means
It’s important to understand: HBM-I values are population-level guidance thresholds. Even if your result is below 2 or 5 ng/mL, personal factors (age, health, pregnancy, cumulative exposure) may influence risk. Exposure should, ideally, be minimized — especially for sensitive individuals (children, pregnant women, immune compromised).
For individuals above HBM-I but below HBM-II, regular monitoring, risk reduction, and possible lifestyle or environmental changes may be advisable, especially if PFAS exposure sources are known.
Key Takeaways & What You Can Do
- PFOA ≤ 2 ng/mL and PFOS ≤ 5 ng/mL in blood plasma are considered “safe” benchmark levels by the HBM-Commission.
- Concentrations above that — especially surpassing HBM-II — may carry increased risk of health issues.
- If you have history of exposure (e.g., use of older firefighting foams, contaminated water, certain consumer products), consider testing and reducing further PFAS exposure.
- Public health and regulatory efforts continue worldwide to limit PFAS use, but personal vigilance still matters.