The current trend in consumers’ preferences for healthy lifestyles resulted in an increased demand for natural products. Many companies replaced synthetic compounds, used as preservatives, flavourings, or active ingredients, with natural ones. Nowadays, essential oils (EOs) and compounds isolated from EOs are regarded as promising and safe alternatives for many synthetic substances used as food additives, food preservatives, repellents, antimicrobial agents, etc. A great dynamic regarding the studies on EOs and in the global market of EOs was also reported. Moreover, the European market of EOs represents a significant share of the global EOs market. According to some recent reports, the European EOs market generated a revenue of more than 11 billion USD per year recently and is expected to reach well over 20 billion USD per year in 2030. The article provides an overview concerning EOs regulation in the European Union (EU). In the EU, the different product categories containing EOs are controlled under specific regulations to enhance product quality and safety. The manuscript highlights the key points of the EU legislation on EOs intended for food purposes, cosmetics, and health care.

aromatic plants, essential oils, food supplements, natural products, regulation

The current trends in consumers’ preferences for healthy lifestyles resulted in an increased demand for natural products. Many companies have been compelled to substitute synthetic compounds, traditionally used as preservatives, flavourings, or active ingredients, with natural ones. Currently, essential oils (EOs) and compounds isolated from EOs are regarded as promising and safe alternatives for many synthetic compounds used as food additives, food preservatives, repellents, antimicrobial agents, etc. (Sharmeen et al. 2021).

The European EOs market represents a significant share of the global EOs market. It has reportedly generated over 11 billion USD in annual revenue in recent years, with projections indicating it may exceed 20 billion USD annually by 2030 (Grand View Research). According to Horizon Databook, the largest revenue share (9.53% in 2023) belongs to the orange essential oil (EO). The European market of EOs is associated with several important key points, including EO industry growth and strong consumption of EOs in the food and cosmetic industries.

The pharmaceutical sector also has a significant share in the consumption of EOs, although there are not many medicines containing EOs registered in the EU. However, there is a great variety of food supplements (FS) containing EOs. Although FS are regulated as “food”, these products represent an important part of the European pharmaceutical market and are often included in the management of many medical conditions. It is a common practice for the FS to be recommended not only to enrich the diet. Many pharmacists and physicians often recommend FS in combination with some medicines for the treatment of the first symptoms of colds, to enhance bone health, and others (Dickinson et al. 2009; Wang et al. 2020; Crawford et al. 2022).

The pharmaceutical industry is often faced with some challenges regarding EOs because of their sensitivity to factors such as light, oxygen, temperature, high volatility, and strong hydrophobicity (Ju et al. 2019). These limitations can be overcome by encapsulating EOs in different drug delivery systems (DDS), which enable controlled release, enhance bioavailability and efficacy, and optimise their pharmacokinetic profile (Cimino et al. 2021). Encapsulation serves as an advanced method to preserve the functionality of EOs while also enabling their controlled release during human metabolism (Shetta et al. 2019). The encapsulation of EOs in DDS offers numerous advantages, including enhanced bioavailability due to DDS adherence to mucous membranes, protection from hydrolysis and oxidation for greater chemical stability, reduced toxicity and volatility, and improved targeting of therapeutic doses, ultimately increasing patient compliance. Various DDS strategies have been explored for EO encapsulation, such as liposomes, solid lipid nanoparticles, self-nano-emulsifying drug delivery systems, and inclusion complexes with cyclodextrins to enhance the stability of their active components (Severino et al. 2015). Particulate delivery systems offer several benefits, including enhancing the organoleptic properties of EOs while also extending their shelf life. Additionally, these systems improve stability, compatibility, and in vivo absorption. Other notable advantages include increased oil solubility and dissolution rates, optimised pharmacokinetics and release profiles, altered biodistribution, and the potential for targeted therapy. A promising recent approach involves the combined encapsulation of EOs with conventional synthetic drugs to enhance efficacy, improve biocompatibility, and mitigate resistance mechanisms (Cimino et al. 2021). As highlighted, the selection of formulation composition and preparation methods is crucial in developing optimal pharmaceutical products (Cimino et al. 2021). The same strategies could be involved in the development of DDSs containing EOs. EO formulations exist in various forms, including liquids (emulsions, micelles, and solutions), semi-solids (gels, liposomes), solids (microcapsules, microcomposites), and aerosols. Semi-solid formulations, such as creams and ointments, have been used for systemic treatment via transdermal absorption. Given their fat-soluble nature, EOs penetrate the skin’s membranes, enter the microcirculation, and are subsequently transported through systemic circulation to various organs (Baptista-Silva et al. 2020). Ointments are formulated by incorporating EOs into a stable base, with considerations for shelf life and application. For instance, ointments based on animal fat have a limited shelf life, necessitating alternative bases that maintain therapeutic efficacy while improving formulation technology (Shaimerdenova 2019). The transformation of liquid EOs into crystalline form allows for the development of powders, granules, and tablets. Through drying techniques such as micro- or nano-spray drying and precipitation, EOs can be processed into solid dosage forms, including soft pills, tablets, and chewing gums. Recently, EO-containing films have been developed, showcasing antimicrobial and antioxidant properties. Oregano EO-based films, for example, have demonstrated significant bioactive potential, while studies on chitosan-based films infused with lemon, thyme, and cinnamon EOs have shown enhanced antimicrobial properties and improved structural integrity, making them a promising option for advanced formulations (Baptista-Silva et al. 2020).

The past decade has witnessed a substantial increase in research focused on the potential applications of EOs, with expectations for their use to broaden across various sectors. Furthermore, projections indicate that the essential oil market may experience a twofold growth within the next five years. This anticipated expansion necessitates thorough examination of the regulatory frameworks governing EOs across diverse industries. The aim of this article is to provide an overview of EOs regulation in the EU. The article highlights data about the procedures for approval in the EU of some of the most popular EOs included in herbal medicinal products (HMP).

The growing demand for chemical-free cosmetics in the EU is regarded as a driving force behind the popularity of EOs in cosmetic formulations. As consumers become more conscious about the ingredients in their skincare/haircare products, there has been a noticeable shift toward more natural, organic, and sustainable alternatives (Sharmeen et al. 2021). Essential oils can be incorporated into cosmetic products for their fragrance, as natural preservatives, or because of their diverse biological activity (antioxidant, antimicrobial, etc.) (Fig. 1). However, using EOs undiluted or in excessive concentrations can lead to skin irritations. In topical applications, they are typically diluted to concentrations ranging from 0.5% to 5%, though some oils may be used at levels up to 10% (Abelan et al. 2022).

Figure 1. 

Applications of EOs in cosmetic products (created with BioRender.com, accessed on 3 February 2025).

All products containing EOs intended to be used for cosmetic purposes in the EU must follow Regulation (EC) № 1223/2009 (Regulation (EC) No 1223/2009 2009). This regulation is the main regulatory framework governing finished cosmetic products placed on the market in the European Union. According to this regulation, a cosmetic product is defined as “any substance or mixture intended to be applied to the external surfaces of the human body, including epidermis, hair, nails, lips, etc., for the sole or main purpose of cleaning, perfuming, changing their appearance, or correcting body odours” (Taobe Consulting 2024). The regulation replaced Directive 76/768/EC, adopted in 1976 (Cosmetic Products 2013), and has some significant strengths compared to the old directive, including better safety requirements for cosmetic products; the introduction of the notion of ‘responsible person’; centralised notification of all cosmetic products placed on the EU market; and reports of serious undesirable effects, colourants, preservatives, and UV filters, which must be explicitly authorised. A technical dossier should prove the safety of the cosmetic product according to Article 10 of the Cosmetics Regulation. This dossier includes comprehensive data on the quality and safety of the essential oils (or the blend, if the product contains multiple oils). Based on the intended use, the responsible person is required to compile the Safety Report as outlined in Annex I of the Cosmetics Regulation, followed by a safety assessment (Taobe Consulting 2024). The safety evaluation of natural cosmetic ingredients follows a risk assessment framework that incorporates hazard identification, hazard characterisation, exposure assessment, and risk characterisation. This process involves detecting chemical, microbial, or physical components that may pose health risks and assessing the probability of both local (such as skin sensitisation, irritation, etc.) and systemic toxicological effects (Manful et al. 2024). According to some reports, EOs used in cosmetics could contain varying levels of heavy metals (Manful et al. 2024). Luka and Akun have reported that contamination from extraction equipment can be a potential source of heavy metal presence in EOs (Luka and Akun 2019). The European Pharmacopoeia (Ph. Eur.) states that the risk associated with EOs depends on factors such as the type of contaminant, the source of the plant material, and the extraction method (EDQM 2021). It was reported that cold-pressed EOs might be associated with a higher risk of contamination with heavy metals compared to distilled ones. Research by Brkljača et al. indicates that olive oil obtained through mechanical pressing had higher lead concentrations than oil extracted via centrifugation (Brkljača et al. 2013). The Ph. Eur. has established heavy metal limits for EOs, setting maximum levels at 5 ppm for lead, 1 ppm for cadmium, and 0.1 ppm for mercury.

Pesticides represent other contaminants that might be present in natural cosmetics (Tascone et al. 2014; Manful et al. 2024). Many studies have reported pesticide residues in different EOs (Lavender, Peppermint, Citrus, etc.). The most commonly found residues include chlorpyrifos, 3,5,6-trichloro-2-pyridinol, carbofuran, carbamate, 3-hydroxycarbofuran, propiconazole, tebuconazole, and others (Bella et al. 2006; Fillâtre et al. 2011; Tascone et al. 2014). As a result, certain cosmetic ingredients must require analyses for pesticides. According to the European Pharmacopoeia’s “Monographs on Essential Oils,” pesticide levels in distilled essential oils rarely exceed permissible limits (Tudi et al. 2022).

The inclusion of EOs in cosmetics is associated not only with some beneficial effects but also with a potential risk for skin sensitisation (Manful et al. 2024). According to Buonomo and Warshaw, approximately eighty EOs, including some of the most popular EOs (tea tree oil, thyme oil, neem oil, and eucalyptus oil), are associated with contact allergies. As a result, skin sensitisation is a key dermal toxicological endpoint in the safety assessment of natural cosmetic ingredients (Buonomo and Warshaw 2021; Manful et al. 2024).

Many cosmetic products contain mixtures of multiple compounds of natural origin, including EOs, fragrances, and other compounds. In general, for the EOs, the chemical composition could vary considerably depending on the geographical origin of the plant material, conditions of harvest, storage, and some further technical processing (Grul’ová et al. 2016; Baranová et al. 2025). In these cases, the cosmetic ingredient should contain data about the qualitative identification and semi-quantitative concentrations of the substances in the mixture (0.1% to <1%, 1% to <5%, 5% to <10%, 10% to <20%, 20%, and more). For mixtures of variable composition, an indication of the range and the maximum levels of the compounds that may be present in the mixture must be included. Specific labelling to reduce the incidence of contact-allergic reactions has been foreseen by the inclusion of potentially sensitising fragrance substances in Annex III to Regulation (EC) No 1223/2009, most of which are naturally found in EOs (EUR-Lex 2023). More specifically, the presence of these compounds must be indicated in the list of the composition of the product on the label when their concentrations in the final product exceed 0.001% in leave-on products or 0.01% in rinse-off products (2003/15/EC). For example, the monoterpene citral is an important fragrance ingredient, which could be found in the EOs isolated from Cymbopogon schoenanthus (L.) Spreng., Litsea cubeba (Lour.) Pers., Melissa officinalis L., and Verbena officinalis L. and other plant species (Capetti et al. 2021). The presence of citral must be indicated in the list of ingredients referred to in Article 19(1), point (g), when the concentration of the compound exceeds 0.001% in leave-on products and 0.01% in rinse-off products. The same requirements are published for citronellol, limonene, α-terpinene, and other compounds. For limonene, the peroxide value is required to be less than 20 mmoles/L, and for α-terpinene, the same value is required to be less than 20 mmoles/L. Although these compounds are regarded as allergens, they are associated with diverse biological activity, and the research on them seems remarkable (Table 1). It is believed that these skin sensitisers react with epidermal proteins through mechanisms that involve radical intermediates (Sahli et al. 2022). In general, these compounds are susceptible to autoxidation, and this is one of the key points in their skin sensitising potential. For example, it is considered that the pure citronellol is safe and non-allergenic. However, when exposed to air, it autoxidises and can cause an allergy. The air-exposed citronellol has a significant skin sensitising potential that is mainly attributed to the hydroperoxides detected at high concentrations in the oxidation mixtures. It is considered that such hydroperoxides can result in the rise of specific antigens. Moreover, the hydroperoxides are believed to react with skin proteins through mechanisms involving radical intermediates (Sahli et al. 2022). The full mechanism of skin sensitising effects is still not clarified.

The Scientific Committee on Consumer Safety has adopted an opinion on fragrance allergens in cosmetic products which expands the list of fragrance allergens considered relevant for consumers and makes it possible to derive a general threshold for substances with a higher number of recorded cases (SCCS/1459/11) (European Commission, Directorate General for Health and Consumers 2012).

The regulation of EOs in cosmetic products is complex and flexible. However, some novel requirements could be introduced for providing better safety. For example, constant monitoring of heavy metals and pesticide levels for every batch should be introduced. Moreover, the chemical composition of every batch should be obligatorily analysed according to the GLP standards. These quality requirements would benefit the customers and their safety. However, this will result in much more expensive production because the quality evaluation involves the work of highly specialised personnel and equipment such as GC-MS and GC-FID, and the quality analyses are often expensive.

In the European Union (EU), regulations governing ЕОs utilised for food applications are stringent, aimed at guaranteeing optimal consumer safety and product quality. For EOs to be considered 100% pure and 100% natural, they need to meet specific standards and to be free from adulteration with synthetic chemicals or other oils. The quality tests include evaluation of the density, optical rotation, and refractive index; gas chromatography analyses; and others. This ensures that the EOs have the expected chemical composition and are not contaminated with impurities or substituted with cheaper oils that mimic the desired aroma. Labelling requirements for diluted oils or blends are also important for transparency. Consumers need to know exactly what they are purchasing, especially if an oil has been diluted or if it is a blend of different oils. This helps prevent misunderstandings about the oil’s strength, quality, or intended use. To enter the European food market, EOs intended for food purposes must comply with several regulations that guarantee food safety, including the General Food Law and Regulation (EC) 1333/2008. The General Food Law is essential in maintaining the safety and quality of food products. The key points of the law cover a broad range of areas—traceability, hygiene, and contaminant control. The core purpose of the General Food Law is to ensure that food products are safe for consumption and that they meet regulatory standards. It sets up the European Food Safety Authority (EFSA)—an independent agency responsible for scientific advice and support. EFSA work is regarded as crucial in maintaining the integrity of the food supply and addressing emerging issues, such as new food additives, contaminants, or novel food products like seaweed hydrocolloids.

The European Pharmacopoeia (Ph. Eur.) serves as the primary reference for the quality control of medicines and their ingredients within the EU. Important data about EOs are included in General Chapter 5.30, titled “Monographs on Essential Oils”, and in many individual monographs that define legally binding quality standards (Essential Oils: Revised Monograph and New General Chapter in the Ph. Eur. 2021). These monographs provide comprehensive analytical methods for the identification and quality assessment of essential oils (EMA 2014b; EDQM 2021).

In the EU, EOs intended for medical use are regarded as herbal medicinal products (HMP). The Committee on HMP in the EU is responsible for scientific opinions on herbal substances and preparations on behalf of the European Medicines Agency (EMA). Companies willing to introduce HMP to the EU market must follow the specific national procedures overseen by national competent authorities (NCAs) (EMA 2025).

The list of NCAs includes but is not limited to the Austrian Agency for Health and Food Safety, the Federal Agency for Medicines and Health Products (Belgium), the Bulgarian Drug Agency, the Agency for Medicinal Products and Medical Devices of Croatia, the Ministry of Health – Pharmaceutical Services (Cyprus), the State Institute for Drug Control (Czechia), the Danish Medicines Agency, the National Agency for the Safety of Medicine and Health Products (France), the National Organisation for Medicines (Greece), the Icelandic Medicines Agency, the Health Products Regulatory Authority (Ireland), and others (EMA 2025).

In general, three regulatory pathways have been developed for the introduction of HMP in the EU market:

• Traditional use registration (Article 16a(1) of Directive 2001/83/EC)—in this case, no clinical tests or safety and efficacy trials are required because there are sufficient safety and efficacy data. The assessment is based mostly on bibliographic data. However, these products must be used for more than 30 years and at least 15 years in the EU.
• Well-established use marketing authorisation (Article 10a of Directive 2001/83/EC)—the assessment is based mostly on bibliographic data. Scientific data about the active substances of the medicinal products have been used in well-established medicines within the EU for at least ten years.
• Stand-alone or mixed application (Article 8(3) of Directive 2001/83/EC)—the safety and efficacy data are based on the company’s own research or a combination of their own studies and well-established scientific data (European Union n.d.).

In the EU, medicines that do not fall under the centralised procedure are authorised by NCAs. This means that each EU Member State has its own authority responsible for the evaluation and approval of medicines intended for the national market. However, the centralised procedure is reserved for certain medicines, including those with a significant public health interest or innovative treatments, which are both authorised by the EMA.

In general, EOs are widely used in the cosmetic and food sectors, while the use within the pharmaceutical sector represents a small part of the global EOs market. The production of EOs is often performed by small companies with limited experience in the manufacturing of active pharmaceutical ingredients (APIs) for pharmaceutical use. All companies that produce APIs in the EU must follow the “Good manufacturing practice for active pharmaceutical ingredients” (EMA 2000). The starting material used in the production of EOs is fresh plant material. The producers of plants for medicinal purposes must follow the “Good agricultural and collection practice for starting materials of herbal origin”.

The European Medicines Agency has published specific guidelines on HMP that provide valuable guidance to pharmaceutical companies in preparing marketing authorisation applications for medicines used in human and veterinary medicine (Table 3).

The European Medicines Agency regularly publishes documents about the scientific conclusions reached by the Committee on Herbal Medicinal Products (HMPC) on the medicinal uses of different EOs (EMA 2016d) (Table 4). The European Union herbal monographs on some aromatic plants are also published on the EMA website (Valerianae aetheroleum 2016). These monographs include data about the qualitative and quantitative compositions, pharmaceutical forms, therapeutic indications and methods of administration, contraindications and precautions, interactions with other medicinal products/other forms of interaction, effects on fertility and pregnancy, effects on ability to drive and use machines, and other information.

Currently, the number of medicines that contain EOs in the EU is relatively low. However, the research on EOs is significant, and it is expected that many novel medicines based on EOs will be introduced soon.

Medical devices (MD) encompass a great variety of products/equipment. In general, all these products are intended for medical purposes. According to the EU regulation, MDs must undergo a conformity assessment to demonstrate they meet all legal safety and utility requirements regulated at the EU Member State level. However, the EMA is also involved in the regulatory process. There are several distinct groups of MDs, and EMA’s responsibility vary among them. Manufacturers can place a CE symbol on their product once it has passed a conformity assessment (CA). The CE symbol derives from the French “Conformité Européenne” (conformity assessment). Generally, the conformity assessment involves evaluation of the manufacturer’s quality system, review of technical data provided by the manufacturer regarding safety, and review of technical data on the performance of the device. In the EU, the regulation about MD is called Regulation (EU) 2017/745, and the companies must comply with it when introducing new MD on the market. It repeals the following directives: Directive 93/42/EEC and Directive 90/385/EEC (EMA 2019). The number of medical devices containing EOs is limited in the EU. Most of these products are used as sprays for nasal congestion and include many different ingredients, including EOs.

The European market of EOs is associated with several important features, including EO industry growth and high levels of utilisation of EOs in the food industry, cosmetic industry, and pharmaceutical sector. The regulations concerning EOs are quite diverse, depending on the purpose of their applications. In the present review, some regulatory challenges associated with EOs were discussed. It is considered that there is a need for additional requirements for manufacturers of FS to ensure the highest levels of safety and quality. Although the regulation on EOs in cosmetic products is complex and detailed, some novel requirements could be introduced for providing better safety for cosmetics in the EU. For example, constant monitoring of heavy metals for every batch should be introduced. Moreover, the chemical composition of every batch should be subject to obligatory analyses according to the Good Laboratory Practice standard. These quality requirements would benefit customer safety. However, this will result in much more expensive production. Many volatile compounds, isolated from EOs and used in the cosmetics industry, are regarded as skin sensitisers because they are susceptible to autoxidation and can provoke allergies. It is essential that their concentrations are monitored for every batch released on the market. The skin-sensitising potential of these compounds is mainly attributed to the hydroperoxides detected at high concentrations in the oxidation mixtures. It is considered that such hydroperoxides can lead to the production of specific antigens. Moreover, it is considered that the hydroperoxides react with skin proteins through mechanisms involving radical intermediates. There is a need for novel strategies for monitoring the skin-sensitising potential of these compounds and constant improvements in the legislative framework to ensure the highest level of safety.

This study was supported by the European Union-NextGener-ationEU, through the National Recovery and Resilience Plan of the Republic of Bulgaria, project № BG-RRP-2.004-0007-C03

Conflict of interest

The authors have declared that no competing interests exist.

Ethical statements

The authors declared that no clinical trials were used in the present study.

The authors declared that no experiments on humans or human tissues were performed for the present study.

The authors declared that no informed consent was obtained from the humans, donors or donors’ representatives participating in the study.

The authors declared that no experiments on animals were performed for the present study.

The authors declared that no commercially available immortalised human and animal cell lines were used in the present study.

Funding

No received funding.

Author contributions

All authors have contributed equally.

Author ORCIDs

Stanislava Ivanova https://orcid.org/0000-0003-1282-7868

Kalin Ivanov https://orcid.org/0000-0002-5689-2920

Yana Gvozdeva https://orcid.org/0000-0002-7622-6060

Radiana Staynova https://orcid.org/0000-0002-8466-3236

Daniela Grekova-Kafalova https://orcid.org/0000-0002-4105-9485

Maria Hristozova https://orcid.org/0000-0001-9815-1496

Data availability

All of the data that support the findings of this study are available in the main text or Supplementary Information.