Baby Safety / Compounds / Amorphous silica nanoparticles (nano-SiO2, E551)

Is Amorphous silica nanoparticles (nano-SiO2, E551) safe for babies and kids?

Context-dependent for kids

(Babies-specific data is limited; this page draws from human pregnant context.) Pregnancy alters the metabolism and distribution of Amorphous silica nanoparticles (nano-SiO2, E551), potentially increasing fetal exposure. The developing embryo/fetus is vulnerable during organogenesis (weeks 3-8) and neurological development. Placental transfer should be assumed.

What is amorphous silica nanoparticles (nano-sio2, e551)?

The IUPAC name is dioxosilane.

Also known as: dioxosilane, SILICON DIOXIDE, Silica, Silicic anhydride.

IUPAC name
dioxosilane
CAS number
7631-86-9
Molecular formula
O2Si
Molecular weight
60.084 g/mol
SMILES
O=[Si]=O
PubChem CID
24261

Risk for babies

Context-dependent

Pregnancy alters the metabolism and distribution of Amorphous silica nanoparticles (nano-SiO2, E551), potentially increasing fetal exposure. The developing embryo/fetus is vulnerable during organogenesis (weeks 3-8) and neurological development. Placental transfer should be assumed.

No specific reproductive toxicity data identified, but pregnancy-specific safety data is limited for most chemicals. Precautionary minimization of exposure is recommended.

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

Risk for pregnant and nursing people

Context-dependent

Pregnancy alters the metabolism and distribution of Amorphous silica nanoparticles (nano-SiO2, E551), potentially increasing fetal exposure. The developing embryo/fetus is vulnerable during organogenesis (weeks 3-8) and neurological development. Placental transfer should be assumed.

No specific reproductive toxicity data identified, but pregnancy-specific safety data is limited for most chemicals. Precautionary minimization of exposure is recommended.

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

Regulatory consensus

8 regulatory and scientific bodies have classified Amorphous silica nanoparticles (nano-SiO2, E551). The classifications differ — that's the data.

AgencyYearClassificationNotes
IARC—Group 1
EPA CTX / IARC—Group 3 - Not classifiable as to its carcinogenicity to humans
EPA CTX / Genetox—Genotoxicity: positive (Ames: positive, 5 positive / 12 negative reports)
EPA CTX / Genetox—Genotoxicity: positive (Ames: positive, 5 positive / 12 negative reports)
EPA CTX / Skin-Eye—Eye Irritation: Category 2 (score: high)
EPA CTX / Skin-Eye—Skin Irritation: Not classified (score: low)
EPA CTX / Skin-Eye—eye irritation: in vivo: Studies Indicate No Significant Irritation (score: low)
EPA CTX / Skin-Eye—skin irritation: in vivo: Studies Indicate No Significant Irritation (score: low)

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 amorphous silica nanoparticles (nano-sio2, e551)

  • 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 Amorphous silica nanoparticles (nano-SiO2, E551):

  • Fragrance-free formulations
    Trade-offs: Consumer preference for scented products
    Relative cost: Lower (ingredient elimination)
  • Essential oil-based fragrances (with disclosure)
    Trade-offs: Natural does not mean safe — many essential oils are skin sensitizers
    Relative cost: 2-5× conventional

Frequently asked questions

What products contain amorphous silica nanoparticles (nano-sio2, e551)?

Amorphous silica nanoparticles (nano-SiO2, E551) appears in: Manufacturing plants (Industrial facilities); Chemical storage areas (Industrial facilities); Factories (Occupational environments); Warehouses (Occupational environments).

Why do regulators disagree about amorphous silica nanoparticles (nano-sio2, e551)?

Amorphous silica nanoparticles (nano-SiO2, E551) has been classified by 8 agencies including IARC, EPA CTX / IARC, EPA CTX / Genetox, EPA CTX / Genetox, EPA CTX / Skin-Eye, 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.

See Amorphous silica nanoparticles (nano-SiO2, E551) in the baby app

Look up products containing amorphous silica nanoparticles (nano-sio2, e551), compare to alternatives, and explore the full data record.

Open in baby View raw API data

Sources (1)
  1. EFSA ANS Panel: Re-evaluation of Silicon Dioxide (E551) as Food Additive — Cannot be considered safe; genotoxicity in vitro; nano-fraction 40–100% by particle number in commercial E551; chronic feeding data gaps; anticaking agent in powdered foods; TDI not established (2018) (2018) — 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 →