Market trends have indicated an opportunity for Shell to expand into the animal vaccine adjuvant market. The company is introducing Shell Ondina X gas-to-liquids (GTL) oils as alternatives to the white mineral oils commonly used in adjuvant emulsions. The purity and hydrocarbon structures of GTL medicinal grade white oils Ondina X can provide considerable benefits.

Shell Ondina X oils for adjuvants

Shell GTL oils are based on Fisher–Tropsch synthesis technology, which converts a very clean feedstock, natural gas, into high-quality, lowaromatic liquid products that offer alternatives to crude-oil-derived mineral oils. Shell Ondina X GTL oils predominantly contain isoparaffinic hydrocarbon structures with long, linear-chain backbones and have been purified by hydrotreatment. The resulting medical grade oils are very pure, virtually free of aromatic, sulphur and nitrogen compounds, and significantly more stable than traditional white oils.

For the adjuvant market, select Shell Ondina X products have the following key features:

  • The degree of hydrocarbon branching is relatively low.
  • The level of cyclic saturated paraffins is very low (<2%).
  • The oils are virtually free of aromatics and polycyclic aromatic hydrocarbons.
  • The oils meet EU pharmaceutical and FDA purity requirements.

Shell Ondina X portfolio range

Shell Ondina X adjuvant oils have been specifically designed and tested to meet the stringent medicinal white oil purity requirements of the major international pharmacopoeias, including the European Pharmacopoeia, the United States Pharmacopeia, the Chinese Pharmacopoeia and the Indian Pharmacopoeia.

The world’s first monograph on our synthetic paraffinic products (Shell Ondina X 409, 411, 415 and 420) is contained in the German Pharmacopoeia (Deutsches Arzneimittelbuch) DAB 2022, to date the only pharmacopeia that specifies levels of mineral oil aromatic hydrocarbons (MOAH) and other components such as polycyclic aromatic hydrocarbons (PAH).


With a well-defined chemical structure, Shell Ondina X adjuvant oils have an outstanding combination of chemical and physical properties such as exceptional purity, low viscosity, low accumulation rate and superior pour point performance, particularly in cold climates.

Exceptional purity
Shell Ondina X oils do not contain polycyclic aromatics or pristane, hopanes or steranes (biomarkers of mineral oil) [3]. They are also virtually free of sulphur and nitrogen compounds. [7]

Well-defined chemical structure
Shell Ondina X oils have homogeneous, isoparaffinic chemical structures with narrow chain-length distributions. They do not contain the complex, plant based hydrocarbon structures of conventional mineral oils [7].

Low viscosity
At the same viscosity, Shell Ondina X oils have lower pour points, which gives them excellent performance at low temperatures.

Lower accumulation rates
Shell Ondina X oils are saturated, low-branched hydrocarbons that metabolise to organic fatty acids that the body can either reuse or degrade by β-oxidation [4, 6]. These oils show low systemic accumulation and rapid elimination. [4]


The physical properties of the Shell Ondina X grades indicate that such oils can be used effectively in adjuvants and would be advantageous in a market currently involving traditional white oils, shark liver oils (squalene and squalene).

Properties of various oils used in adjuvants for animal vaccine compared with GTL oils are tabulated as below.

White Oil    
Hydrocracked oil    
Shell Ondina X 409   
Shell Ondina X 411   
Shell Ondina X 415   
Chemical class   
Saturated hydrocarbon   
Saturated hydrocarbon   
Saturated hydrocarbon   
Saturated hydrocarbon   
Saturated hydrocarbon   
Saturated hydrocarbon   
Unsaturated hydrocarbon   
Mineral oil    
Mineral oil    
Shark liver   
Shark liver   
Boiling range (°C)    
280 - 400   
280 - 320    
270 - 295   
305 - 355   
320 - 380   
Kinematic viscosity (cSt)   
7.2 at 40°C   
4.1 at 40°C   
3.5 at 40°C   
6.0 at 40°C   
9.3 at 40°C   
34 at 20°C   
14 at 25°C   
Pour point (°C)   
Density (kg per cubic meter)   
840 at 15°C   
813 at 15°C   
785 at 15°C   
800 at 15°C   
806 at 15°C   
805 at 20°C   
858 at 20°C   
Oxidation stability    
Isomer typres   
Iso-, n- and alkylated cycloparaffins (>50%)   
Iso-, n- and alkylated cycloparaffins (>50%)   
Linear and low-branched hydrocarbons; n-paraffins <15%   
Linear and low-branched hydrocarbons; n-paraffins <1%   
Linear and low-branched hydrocarbons; n-paraffins <10%   
Highly branched, saturated hydrocarbon   
Highly branched, unsaturated hydrocarbon-iso-olefin   
Carbon number range   
C15   - C30   
C15   - C19   
C15   - C19   
C18   - C24   
C17   - C31   

The results of 28-d OECD toxicity testing indicate that Shell Ondina X 409 and X 411 oils are classified as readily biodegradable, whereas the Shell Ondina X 415 grade is classified as inherently biodegradable. These excellent biodegradability characteristics and the very low systemic toxicological risks for the high-purity medical grade Shell Ondina X GTL oils mean that they offer a high level of safety for use in adjuvants in animal vaccines.

Customers wanting to use Shell Ondina X oils in adjuvants can be assured of high purity grades (free of aromatics and heavy metals) and microbefree products through the high temperature of the hydrotreatment process and subsequent appropriate storage and handling practices, and specific packaging of products (when required).


Shell Ondina X oils have numerous key benefits that make them smart alternative adjuvants to conventional mineral oils and other, nonmineral-based products such as squalene [3].

Safer for animals
Less injection pressure is required. These oils also show low systemic accumulation and rapid elimination [4].

Better versatility
Better for cold-climate applications, for example, high-latitude fisheries, where oils with better flowability are preferable, or when different permeability rates are required.

Safer for humans and ecosystems
Shell Ondina X oils are metabolised as much as six times faster than conventional mineral oils in certain applications [4]. This lowers accumulation rates and reduces the risk of residual oil remaining in animal tissue and, thus, entering the human food chain [4]. It also reduces the risk of oil transferring into local ecosystems because of favourable biodegradation properties [5]

Scalable supply
The origin of Shell Ondina X oils is the Pearl GTL plant in Qatar, the largest facility in the world. We have GTL product storage hubs around the world in different regions including North America, the Middle East, Europe, Hong Kong, Singapore. This means that Shell can supply pharmaceutical grade oils and support vaccine production even when demand is high.


  1. Aucouturier J, Dupuis L, Ganne V: Adjuvants designed for veterinary and human vaccines. Vaccine 2001, 19(17-19):2,666–2,672.
  2. Kuroda Y, Akaogi J, Nacionales DC, Wasdo SC, Szabo NJ, Reeves WH, Satoh M: Distinctive patterns of autoimmune response induced by different types of mineral oil. Toxicological Sciences 2004, 78(2):222-228.
  3. Shivaprasad P, de Azevedo, E, Carrillo, J-C, Brosell, A: Animal vaccine adjuvants: A new use for gas-to-liquids oils. Shell TechXplorer Digest 2021: 66-70.
  4. Carrillo J-C, Shen H, Momin F, Kral O, Schnieder H, Kühn S: GTL synthetic paraffin oil shows low liver and tissue retention compared to mineral oil. Food and Chemical Toxicology 2022, 159:112701.
  5. Whale GF, Dawick J, Hughes CB, Lyon D, Boogaard PJ: Toxicological and ecotoxicological properties of gas-to-liquid (GTL) products. 2. Ecotoxicology. Critical Reviews in Toxicology 2018, 48(4):273–296.
  6. Cravedi J, Thibaut R, Tulliez J, Perdu E: Comparative in vitro study of the biotransformation of n-alkanes by liver and small intestine microsomes from different rat strains. Toxicology Letters 2012, 205:S188.
  7. Disclosed anonymously: Use of Synthetic Medicinal White Oils in Animal Vaccines. Research Disclosure database number 666021. Published in the October 2019 paper journal. Published digitally 02 September 2019 12:31 UT.

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