Baby Safety / Compounds / Iron(II) sulfate (ferrous sulfate)

Is Iron(II) sulfate (ferrous sulfate) safe for babies and kids?

Elevated risk for kids

Infants are extremely vulnerable to Iron(II) sulfate (ferrous sulfate) due to immature blood-brain barrier, higher gastrointestinal absorption rates (40-50% vs 3-10% in adults), and rapidly developing neurology. Even trace exposure can cause irreversible neurodevelopmental harm.

What is iron(ii) sulfate (ferrous sulfate)?

The IUPAC name is iron(2+) sulfate.

Also known as: iron(2+) sulfate, FERROUS SULFATE, Iron(II) sulfate, Ferrous sulfate anhydrous.

IUPAC name: iron(2+) sulfate
CAS number: 7720-78-7
Molecular formula: FeO4S
Molecular weight: 151.91 g/mol
SMILES: [O-]S(=O)(=O)[O-].[Fe+2]
PubChem CID: 24393

Risk for babies

Elevated risk

Neonates and infants up to 12 months have incomplete blood-brain barrier development, immature Phase I/II metabolic enzymes (particularly CYP3A4, UGT1A1), and higher gastrointestinal permeability. Equivalent doses produce higher internal concentrations and longer residence times.

What to do: Minimize infant exposure through source control. For breastfeeding mothers: reduce maternal exposure. For formula-fed infants: use certified low-migration bottles and verified water sources. Consult pediatrician regarding any concerns.

Risk for pregnant and nursing people

High risk

Pregnancy increases vulnerability to Iron(II) sulfate (ferrous sulfate). Heavy metals cross the placenta, accumulate in fetal tissue, and interfere with neurodevelopment. Maternal bone resorption during pregnancy mobilizes stored metals.

Known reproductive toxicant (GHS H360) or confirmed endocrine disruptor. Placental transfer is presumed. Fetal exposure during critical developmental windows may cause structural malformations, growth restriction, or functional deficits.

What to do: Minimize exposure during pregnancy and lactation. Consult healthcare provider regarding specific risks. Consider alternative products with lower hazard profiles.

Regulatory consensus

3 regulatory and scientific bodies have classified Iron(II) sulfate (ferrous sulfate). The classifications differ — that's the data.

Agency	Year	Classification
IARC	2020	Not evaluated by IARC for carcinogenicity — ferrous sulfate (FeSO4) is an essential iron supplement and industrial reagent; iron is an essential trace element required for hemoglobin synthesis and cellular respiration; not classified as a carcinogen; primary regulatory concerns are acute iron toxicity from overdose (particularly pediatric) and GI irritation; classified EU Acute Tox 4 (H302) by oral route; high aquatic toxicity (Aquatic Acute 1, Chronic 1) noted for concentrated FeSO4 solutions
EPA CTX / Genetox	—	Genotoxicity: positive (Ames: positive, 3 positive / 3 negative reports)
EPA CTX / Genetox	—	Genotoxicity: positive (Ames: positive, 3 positive / 3 negative reports)

Regulators apply different standards of evidence — animal-data weighting, exposure-pattern assumptions, epidemiological power thresholds — which is why two scientific bodies can review the same data and reach different conclusions. The disagreement is the data.

Where kids encounter iron(ii) sulfate (ferrous sulfate)

Industrial Facilities — Manufacturing plants, Chemical storage areas, Waste treatment sites
Occupational Environments — Factories, Warehouses, Transportation vehicles

Safer alternatives

Lower-risk approaches that achieve a similar outcome to Iron(II) sulfate (ferrous sulfate):

Enzyme or biocatalysts where applicable
Trade-offs: Temperature/pH sensitivity. Higher cost for some applications.

Relative cost: 1.2-2×

Frequently asked questions

Is iron(ii) sulfate (ferrous sulfate) safe for kids?

What products contain iron(ii) sulfate (ferrous sulfate)?

Iron(II) sulfate (ferrous sulfate) appears in: Manufacturing plants (Industrial facilities); Chemical storage areas (Industrial facilities); Factories (Occupational environments); Warehouses (Occupational environments).

What should I do if my child is exposed to iron(ii) sulfate (ferrous sulfate)?

Minimize infant exposure through source control. For breastfeeding mothers: reduce maternal exposure. For formula-fed infants: use certified low-migration bottles and verified water sources. Consult pediatrician regarding any concerns.

Why do regulators disagree about iron(ii) sulfate (ferrous sulfate)?

Iron(II) sulfate (ferrous sulfate) has been classified by 3 agencies including IARC, EPA CTX / Genetox, EPA CTX / Genetox, with differing conclusions. Regulators apply different standards of evidence (animal data weighting, exposure-pattern assumptions, epidemiological power thresholds), which is why two scientific bodies can review the same data and reach different conclusions. See the regulatory consensus table on this page for the full picture.

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Look up products containing iron(ii) sulfate (ferrous sulfate), compare to alternatives, and explore the full data record.

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Sources (1)

Ferrous Sulfate FeSO4 Iron Deficiency Anemia First-Line Supplement 150-200 mg Elemental Fe; DMT1 Fe2+ Bioavailability Vitamin C Phytate Inhibition; Pediatric Iron Poisoning PPPA Child-Resistant Packaging 20-60 mg/kg Lethal; Deferoxamine Chelation Antidote; EU Cement Regulation Cr(VI) Reduction 2 mg/kg Wet Cement; Water Treatment Coagulation Flocculation Fe(OH)3; Acid Mine Drainage Ochreous Yellow Boy Benthic; IARC Not Evaluated; EU CLP H302 Aquatic Acute 1 H400; Hemochromatosis Iron Overload (2020) — regulatory

Reference data, not professional advice. Aggregates publicly available regulatory and scientific data; not a substitute for veterinary, medical, legal, or regulatory advice. Why we built ALETHEIA →