Is Silver (nanoparticles) safe on a child's skin?

Silver nanoparticles are identified as potential reproductive toxins by the European Chemicals Agency (ECHA).

Why here

Dermal exposure in children to products containing silver nanoparticles could lead to systemic absorption, which may pose reproductive toxicity risks.

What would have to be true

General dermal exposure to silver nanoparticles in consumer products.

The other side

The Scientific Committee on Consumer Safety (SCCS) later concluded that micron-sized particulate silver is safe for dermal use at specified concentrations, based on new data showing it does not penetrate the skin. However, this conclusion specifically refers to micron-sized particles (100 nm to 1 mm) and does not negate the ECHA's classification for nanoparticle forms (1-100 nm), and the SCCS itself has stated it cannot conclude on the safety of colloidal silver in nano form due to data gaps.

The long-term safety of silver nanoparticles in products intended for children, particularly regarding chronic dermal exposure, is not well understood due to significant data gaps in regulatory assessments.

Why here

Children are a vulnerable population, and the widespread use of nanosilver in consumer products necessitates comprehensive safety data for this specific exposure route and demographic.

What would have to be true

Chronic dermal contact with products containing silver nanoparticles.

Silver nanoparticles, particularly those smaller than 45 nm, can penetrate intact human skin and deposit in the dermis, potentially leading to localized bluish-gray skin discoloration (argyria) with cumulative exposure.

Why here

Direct application of products containing silver nanoparticles to the skin of children can lead to dermal absorption and accumulation.

What would have to be true

Dermal contact with products containing silver nanoparticles, especially those with particle sizes below 45 nm. Cumulative exposure in humans at doses ranging from 70–1500 mg silver/kg body weight has been associated with generalized argyria.

The other side

Some commercial sources and regulatory opinions for micron-sized silver suggest that silver nanoparticles do not penetrate human skin or remain confined to the outermost layers.

Silver nanoparticles have been linked in animal studies to systemic toxicity and accumulation in various organs, including the kidney, muscle, bone, liver, and heart, following dermal application at high concentrations.

Why here

Dermal leave-on products allow for prolonged skin contact, and while skin penetration of intact skin by AgNPs is debated, some studies suggest it can occur, especially for smaller particles or compromised skin, leading to potential systemic exposure.

What would have to be true

Dermal application of silver nanoparticles, with potential for systemic absorption and accumulation in organs. Animal studies used high concentrations (100, 1000, 10000 ppm).

Silver nanoparticles from cosmetic products can be released into the environment during use and disposal, transforming into potentially toxic silver ions or other species that can harm aquatic and terrestrial organisms.

Why here

Leave-on cosmetic products eventually get washed off, contributing to wastewater and environmental release of silver nanoparticles.

What would have to be true

Release of silver nanoparticles from cosmetic products into wastewater systems.

The European Food Safety Authority (EFSA) has concluded that there is insufficient information to assess the safety of silver as a food additive (E 174) and therefore, silver nanoparticles are not allowed in food supplements or food packaging unless authorized.

Why here

This directly addresses the regulatory status and safety assessment for ingestion as a food additive or in food contact materials.

What would have to be true

Ingestion as a food additive (E 174) or migration from food packaging, with EFSA providing migration limits of <0.05 mg/L in water and <0.05 mg/kg in food.

Agencies such as the U.S. Food and Drug Administration (FDA), the European Chemicals Agency (ECHA), and the World Health Organization (WHO) have issued public statements discouraging the oral use of colloidal silver, citing the absence of demonstrated therapeutic benefits and potential for cumulative toxicity. The FDA has not approved colloidal silver for any medical treatment.

Why here

This directly addresses the regulatory stance on oral consumption of colloidal silver, often marketed as a dietary supplement.

What would have to be true

Oral consumption of colloidal silver dietary supplements.

Oral ingestion of silver nanoparticles has been linked in animal studies to bioaccumulation in internal organs such as the liver, spleen, kidneys, brain, and testes, leading to organ damage including liver and renal damage, and bile-duct hyperplasia.

Why here

Ingested nanoparticles are absorbed and distributed throughout the body, accumulating in various organs.

What would have to be true

Oral exposure in rats at doses ≥ 125 mg/kg/day for 90 days showed liver and renal damage, with a No Observed Adverse Effect Level (NOAEL) of 30 mg/kg/day.

Oral ingestion of silver nanoparticles has been found in mouse studies to induce genomic instability and DNA damage, including large DNA deletions in developing embryos, irreversible chromosomal damage in bone marrow, and oxidative DNA damage, suggesting a potential for cancer risk.

Why here

Ingested nanoparticles can reach various tissues and interact with genetic material.

What would have to be true

Oral exposure to polyvinylpyrrolidone (PVP)-coated AgNPs in mice.

Animal studies suggest that maternal oral exposure to silver nanoparticles can cross the placental barrier and interfere with fetal development, leading to fetal developmental alterations such as craniofacial malformations, spinal deformities, and reduced fetal weight.

Why here

Ingested nanoparticles can be absorbed and distributed to the placenta and fetus.

What would have to be true

Oral administration of 70 nm AgNPs at 1 mg/kg/day to pregnant mice from gestational day 1 to 14.