Are natural ingredients safer?

Factsheets
How to cite: Lagut A, Wong M, Novakovich J. Are natural ingredients safer?. Beauty SciComm Group. August 18, 2023. Accessed June 21, 2024. https://beautyscicomm.com/are-natural-ingredients-safer/

Natural cosmetics are trending. But are they inherently safer to use? Here’s the science.

What is “natural”?

Natural generally means an ingredient obtained from nature, with little or no modification. This is often contrasted with “synthetic”, which means made in a lab, often from petrochemical sources.

However, the lines are often blurred:

As an example, the ISO 16128 standard considers water as a natural ingredient while some other “naturality” calculations do not.

Are natural ingredients safer?

Many ingredients can be either sourced from nature or synthesised in a lab. Regardless of the origin, the main ingredient will be the same. For example, red iron oxide contains iron and oxygen in a ratio of 2 to 3, whether natural or synthetic.

The origin does not tell us about the safety – natural and synthetic iron oxide will interact the same way with the body. However, different contaminants may be present depending on the exact source.

For example, natural sources of iron oxides are often contaminated with unacceptable levels of heavy metals, like lead. As a consequence, only synthetic versions are permitted in some regions such as the US. On the other hand, some synthetic ingredients may still contain some of the starting materials or solvents.

Many common allergens are also natural. Cosmetics containing natural ingredients can cause serious adverse reactions like allergic contact dermatitis, photosensitisation, contact urticaria and even anaphylaxis. A 2022 survey found that almost 90% of “natural” skincare products contained at least one of the top 100 allergens known to trigger reactions in people. There was an average of 4.5 allergens per product – many of these were natural fragrance ingredients.

Ultimately, the source of an ingredient doesn’t determine its safety. Both natural and synthetic ingredients need to be assessed for safety, which includes the levels of any contaminants.

A simplified way to think about this is: if there’s a bear running towards you, you don’t necessarily care if it was born in the forest or in a zoo, the urgent safety concern is the harm it could cause you.

bear natural

We have a bias for “natural”

Our brains developed many shortcuts (cognitive biases) to more quickly make sense of the world. However, these can sometimes lead us down the wrong path.

One of these is “appeal to nature”, where something seems safer, correct or superior purely due to its natural origin. This can be very convincing, even though we know that nature produces plenty of dangers (like poisonous plants and animals).

This effect is well-studied in psychology, and is effectively utilised in marketing. An interesting case study in 2020 presented a lip balm in two different ways. When the mineral oil in the lip balm was labelled “naturally sourced”, consumers perceived it as being safer than when it was “synthetic mineral oil saturated hydrocarbon”.

There is nothing wrong with preferring products with more natural ingredients. However, the positive notions related to nature shouldn’t replace appropriate safety assessments. And chemophobic insinuations that synthetic ingredients are somehow unsafe or that “all chemicals should be avoided” are misleading – everything is made of chemicals, including air and water.

all natural strawberry
James Kennedy Monash

Is natural more sustainable?

Like for safety, the origin of the material doesn’t tell you about its sustainability. Even though natural ingredients are renewable, they can have large impacts – it needs to be assessed on a case-by-case basis.

According to the 2019 IPBES report, agriculture was the largest contributor to biodiversity loss, particularly its expansion into intact ecosystems like forests. It is also a significant contributor to carbon emissions. For example, vitamin production is far more sustainable through synthetic routes than from natural sources.

However, many natural ingredients are byproducts of other processes, and this can make them a more sustainable option. For example, biodiesel production makes excess glycerin, which is often used in cosmetics – synthesising glycerin would not be economical or sustainable.

Both natural and synthetic have their place

There are many examples of natural and synthetic ingredients that are very important in cosmetics.

Formulating with natural ingredients

As we have seen, ingredients of natural origin can be very useful. Some complexities to take into account when formulating with natural ingredients:

  • Being natural doesn’t guarantee safety, and synthetic ingredients aren’t “all toxic”. Safety assessments are necessary for all ingredients.
  • Nature produces many substances that can have harmful effects like lead, mercury, asbestos, poisonous plants and animals.
  • The safe use of natural ingredients can be challenging due to their complex and varied chemical compositions. Variations arise from the harvesting region, season and preparation method.
  • Extracts can be sourced from the whole plant, or from specific parts – leaves, roots, flowers, fruits, seeds or berries – these all have a different chemical composition.
  • Natural ingredients may not be a more sustainable choice. For example, agriculture can have large impacts. Additionally, farming in historically pillaged regions comes with its own socio economic, political and environmental complexities.
  • Many natural products claim to be preservative-free, but this can be dangerous as cosmetics are good environments for microbial growth.
  • Many natural products have lower stability, shorter shelf lives and are more prone to separation.

Takeaways

Ingredients aren’t “good” or “bad” just because they’re natural or synthetic. Both have useful properties in cosmetics.

At the end of the day, ingredients should be chosen due to their properties, and formulated to create safe products.

References

Organic, natural and of natural origin, what’s the difference between these types of ingredients? Cosmebio. Published 2019. Accessed May 14, 2023.

International Organization for Standardization. Guidelines on technical definitions and criteria for natural and organic cosmetic ingredients and products — Part 1: Definitions for ingredients (ISO 16128-1:2016). International Organization for Standardization, 2016.

US Food and Drug Administration. CFR—Code of Federal Regulations, Title 21, Volume 1 (21CFR73.2250). https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=73.2250. Accessed May 14, 2023.

Young PA, Gui H, Bae GH. Prevalence of contact allergens in natural skin care products from US commercial retailers. JAMA Dermatol. 2022;158(11):1323-1325.  doi:10.1001/jamadermatol.2022.3180

Appeal to Nature. Logically Fallacious. Published 2013. Accessed May 14, 2023.

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Kennedy J. Ingredients of an all-natural strawberry. James Kennedy. Published August 21, 2014. Accessed May 14, 2023.

IPBES, Brondizio ES, Settele J, Díaz S, Ngo HT, eds. Global assessment report on biodiversity and ecosystem services of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services. IPBES secretariat; 2019. doi:10.5281/zenodo.3831673

Eggersdorfer M, Laudert D, Létinois U, et al. One hundred years of vitamins-a success story of the natural sciences. Angew Chem Int Ed Engl. 2012;51(52):12960-12990. doi:10.1002/anie.201205886

Mandalari G, Bennett RN, Bisignano G, et al. Characterization of flavonoids and pectins from bergamot (Citrus bergamia Risso) peel, a major byproduct of essential oil extraction. J Agric Food Chem. 2006;54(1):197-203. doi:10.1021/jf051847n

Barbulova A, Colucci G, Apone F. New Trends in cosmetics: by-products of plant origin and their potential use as cosmetic active Ingredients. Cosmetics. 2015;2(2):82-92. doi:10.3390/cosmetics2020082

Peschel W., Sánchez-Rabaneda F., Diekmann W., Plescher A., Gartzía I., Jimenez D., Lamuela-Raventos R.M., Buxaderas S., Codina C. An industrial approach in the search of natural antioxidants from vegetable and fruit wastes. Food Chem2006;97:137–150. doi:10.1016/j.foodchem.2005.03.033

Sahani S, Upadhyay SN, Sharma YC. Critical review on production of glycerol carbonate from byproduct glycerol through transesterification. Ind Eng Chem Res. 2021;60(1):67–88. doi:10.1021/acs.iecr.0c05011

US Food and Drug Administration. CFR—Code of Federal Regulations, Title 21, Volume 5 (21CFR347.10). https://www.ecfr.gov/current/title-21/chapter-I/subchapter-D/part-347/subpart-B/section-347.10. Accessed May 14, 2023.

American Chemical Society National Historic Chemical Landmarks. The Development of Tide Synthetic Detergent. Accessed May 14, 2023.

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