What Is 1.4 Dioxane? Understanding Its Risks and How to Test Its Level Using HPLC
The safety of cosmetic products is determined not only by the active ingredients and other ingredients listed on the label. During the manufacturing process, certain compounds may be formed as contaminants or byproducts and may not be intentionally included in the ingredient list.
One such compound is 1.4 dioxane, which may be present at very low levels in certain cosmetic products. Due to its toxicological concerns, the presence of 1.4 dioxane needs to be controlled and may be considered as one of the parameters in cosmetic product safety evaluation.
Table of Content:
- How Can 1.4 Dioxane Be Formed in Cosmetic Products?
- What Types of Products May Contain 1,4 Dioxane?
- Why Is 1,4 Dioxane Testing Important for Cosmetic Products?
- How Is 1,4 Dioxane Tested Using HPLC?
How Can 1.4 Dioxane Be Formed in Cosmetic Products?
1.4 Dioxane is not intentionally added as a cosmetic ingredient. It can be formed as a byproduct during the manufacturing of certain cosmetic ingredients, particularly those produced through ethoxylation processes.
Ethoxylation is widely used in the production of various surfactants, foaming agents, emulsifiers, and other ingredients containing ethoxy or polyethylene glycol groups. Certain groups of ingredients may be associated with the potential presence of 1.4 dioxane, including ingredients containing names or components such as PEG, polyethylene, polyethylene glycol, polyoxyethylene, and oxynol.
The U.S. Food and Drug Administration explains that 1.4 dioxane may occur as a trace contaminant as a result of the manufacturing processes used to produce these ingredients. Because it is formed as a byproduct, 1.4 dioxane is not necessarily listed as an ingredient on cosmetic product labels.
Therefore, manufacturing process control and testing of raw materials and finished products can play an important role in controlling this contaminant.
What Types of Products May Contain 1,4 Dioxane?
The potential presence of 1.4 dioxane is mainly associated with cosmetic products containing ingredients produced through ethoxylation. Products that have been investigated for 1.4 dioxane include shampoos, conditioners, cleansers, liquid soaps, body washes, lotions, creams, sunscreens, bath products, and hair care products.
Studies involving various cosmetic products have shown that the presence and concentration of 1,4 dioxane can vary depending on the product type, raw materials, and manufacturing processes involved. Therefore, the presence of an ingredient that has the potential to generate 1,4 dioxane does not automatically mean that the finished product contains a harmful concentration of the compound.
Potential contamination can be controlled through appropriate raw material selection, manufacturing process control, and testing of 1,4 dioxane levels in relevant raw materials or finished products.
Why Is 1,4 Dioxane Testing Important for Cosmetic Products?
1,4 Dioxane has received significant attention because it is classified as a potential human carcinogen. The National Toxicology Program considers 1,4 dioxane to be reasonably anticipated to be a human carcinogen based on evidence of carcinogenicity from animal studies, while available epidemiological data in humans are insufficient to establish a clear relationship.
The U.S. Environmental Protection Agency also classifies 1,4 dioxane as likely to be carcinogenic to humans. As a potential contaminant, testing for 1,4 dioxane can help manufacturers determine whether the compound is present in raw materials or finished products and at what concentration.
Analytical data can also support quality evaluation, manufacturing process control, formulation development, and product safety documentation. The U.S. Food and Drug Administration has monitored 1,4 dioxane levels in cosmetic products for several decades and has reported decreasing levels over time as manufacturing processes have improved.
How Is 1,4 Dioxane Tested Using HPLC?
The analysis of 1,4 dioxane using HPLC, or High Performance Liquid Chromatography, can be performed using a chromatographic method that has been appropriately developed and validated for the specific product matrix. One published method uses solid phase extraction, or SPE, as a sample preparation step, followed by analysis using a reversed phase column with UV detection at 200 nm and a methanol and water mobile phase.
This approach has been applied to the analysis of 1,4 dioxane in various cosmetic products. The selection of an appropriate analytical method should consider the characteristics of the product matrix, target concentration, required sensitivity, and availability of a suitable validated method.
Appropriate laboratory testing can provide quantitative analytical data to support the quality and safety evaluation of cosmetic products.
Verify 1.4-Dioxane Levels Through Laboratory Testing
The presence of 1,4-dioxane cannot always be identified from a product's appearance. Laboratory analysis is therefore important for obtaining objective data on the presence and concentration of this compound.
Through Chemical Compound Testing using an appropriate analytical method, 1,4-dioxane levels can be evaluated to support product quality and safety control. Contact IML Testing & Research today and discuss your 1,4-dioxane testing requirements with our team!
Author: Elmira
Editor: Lina
References
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National Toxicology Program. (2021). 1,4 Dioxane. Report on Carcinogens. https://ntp.niehs.nih.gov/sites/default/files/ntp/roc/content/profiles/dioxane.pdf
Park, S., et al. (2019). The determination of 1,4 dioxane in cosmetic products by gas chromatography with tandem mass spectrometry. Journal of Chromatography A, 1607, 460400. https://doi.org/10.1016/j.chroma.2019.460400
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U.S. Environmental Protection Agency. (2013). 1,4 Dioxane (CASRN 123 91 1). Integrated Risk Information System. https://iris.epa.gov/ChemicalLanding/&substance_nmbr=326
U.S. Food and Drug Administration. (2024). Cosmetics safety Q&A: Contaminants. https://www.fda.gov/cosmetics/resources-consumers-cosmetics/cosmetics-safety-qa-contaminants
