Description

Colloidal Gold consists of tiny gold particles suspended in a liquid. This form of gold is used in various cosmetic and skincare products due to its purported anti-aging and rejuvenating properties. Colloidal Gold is known for its ability to enhance skin appearance, improve elasticity, and provide a radiant glow.

Chemical Composition and Structure:

Gold Particles: Microscopic particles of gold, typically ranging from 1 to 100 nanometers in size.
Liquid Medium: Often suspended in water or a hydrating solution, maintaining stability and preventing agglomeration of the gold particles.
Colloidal Solution: A stable dispersion of gold particles in a liquid.

Physical Properties:

Appearance: A golden or yellowish liquid, depending on the concentration and size of the gold particles.
Odor: Generally inodorous or with a very faint metallic scent.
Texture: Smooth and fluid, with a consistency similar to water.

Production Process:

The production of Colloidal Gold involves:

Preparation: Creation of a gold solution using high-purity gold.
Nanoparticle Formation: Gold is reduced to nanoparticles through various chemical or physical methods.
Stabilization: The gold nanoparticles are stabilized in a liquid medium to prevent aggregation and ensure even dispersion.
Formulation: Incorporation of Colloidal Gold into cosmetic and skincare products.

Applications:

Cosmetics: Used in serums, creams, and masks for its potential to improve skin appearance, texture, and elasticity.
Skincare: Applied in products aimed at reducing signs of aging, providing a youthful glow, and enhancing overall skin radiance.
Medical: Occasionally used in therapeutic applications and research due to its biocompatibility.

Environmental and Safety Considerations:

Niżnik, Ł., Noga, M., Kobylarz, D., Frydrych, A., Krośniak, A., Kapka-Skrzypczak, L., & Jurowski, K. (2024). Gold Nanoparticles (AuNPs)—Toxicity, Safety and Green Synthesis: A Critical Review. International Journal of Molecular Sciences, 25(7), 4057.
Abstract. Abstract
In recent years, the extensive exploration of Gold Nanoparticles (AuNPs) has captivated the scientific community due to their versatile applications across various industries. With sizes typically ranging from 1 to 100 nm, AuNPs have emerged as promising entities for innovative technologies. This article comprehensively reviews recent advancements in AuNPs research, encompassing synthesis methodologies, diverse applications, and crucial insights into their toxicological profiles. Synthesis techniques for AuNPs span physical, chemical, and biological routes, focusing on eco-friendly “green synthesis” approaches. A critical examination of physical and chemical methods reveals their limitations, including high costs and the potential toxicity associated with using chemicals. Moreover, this article investigates the biosafety implications of AuNPs, shedding light on their potential toxic effects on cellular, tissue, and organ levels. By synthesizing key findings, this review underscores the pressing need for a thorough understanding of AuNPs toxicities, providing essential insights for safety assessment and advancing green toxicology principles.

Scientific Committee on Consumer Safety - SCCS/1629/21 Final Opinion on
Gold (nano), Colloidal Gold (nano), Gold Thioethylamino Hyaluronic Acid (nano) and Acetyl heptapeptide-9 Colloidal gold (nano)
Conclusion
1. In view of the above, and taking into account the scientific data provided, does the SCCS consider the nanomaterials A, B and C are safe when used in leave-on cosmetic products according to the maximum concentrations and specifications reported in the attached list, taking into account reasonably foreseeable exposure conditions?
The SCCS has considered all the information provided by the Notifiers and is of the opinion that it is not possible to carry out safety assessment of the nanomaterials (Gold, Colloidal Gold and Surface Modified Gold) due to limited or missing essential information. Much of the information provided on toxicity relates to gold as such, and it is not possible to determine the relevance of the data for nano-forms of any of the materials under the current evaluationdue to the absence of full study reports.
Detailed data and information need to be provided on physicochemical characterisation and toxicological evaluation, along with experiment performance to allow safety assessment of the nanomaterials.
In regard to surface modified gold, all notifications relating to Acetyl heptapeptide-9 Colloidal gold (nano) were withdrawn by the Notifiers and therefore only Gold Thioethylamino
Hyaluronic Acid has been considered in this Opinion.

2. Does the SCCS have any further scientific concerns with regard to the use of materials A, B and C in nano form in cosmetic products?
The information obtained from scientific literature suggests possible systemic uptake of gold nanoparticles which may lead to accumulation in certain organs - notably the liver and spleen. In addition, the available data from literature indicate potential mutagenic/genotoxic effects of gold nanomaterials. These indications raise an alert that warrants further safety evaluation of gold nanomaterials when used as cosmetic ingredients. In the absence of sufficient data to allow safety assessment, the SCCS has considered these aspects and has concluded that there is a basis for concern that the use of Gold (nano), Colloidal Gold (nano) and Surface Modified Gold (nano) materials in cosmetic products can pose a risk to the consumer. The SCCS concerns for consumer safety in this regard are detailed in Annex II.
The SCCS would be ready to assess any evidence provided to support the safe use of this materials in cosmetic products.

INCI Functions:


Antimicrobial agent. This ingredient is able to suppress or inhibit the growth and replication of a broad spectrum of microorganisms such as bacteria, fungi and viruses by making the stratum corneum temporarily bactericidal and fungicidal.

Skin conditioning agent - Miscellaneous. This ingredient has the task of modifying and improving the condition of the skin when it is damaged or dry, reducing flaking and restoring its elasticity.
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