Composition and Therapeutic Properties of Ozokerite

Ozokerite is a wax-like product of petroleum origin, made up of a mixture of solid paraffin-series hydrocarbons together with a greater or lesser admixture of the liquid and gaseous hydrocarbons found in crude oil. Also known as earth wax, mineral wax, or ceresin wax, it appears in cosmetic formulations under the INCI name Ozokerite and is one of the oldest naturally occurring mineral waxes used in industry and medicine.

What is ozokerite: definition and origin

Ozokerite is a naturally occurring mineral wax composed principally of solid hydrocarbons, forming as petroleum migrates through rock fissures and its lighter fractions evaporate, leaving a waxy residue behind. This origin explains why ozokerite always occurs near oil-bearing deposits and why its composition mirrors the paraffin fraction of crude oil. In its raw mined state it ranges from a soft, sticky mass to a hard, brittle solid depending on how much liquid hydrocarbon remains trapped within it.

Etymology and history of the name ozokerite

The name ozokerite derives from the Greek words for "smell" (ozo) and "wax" (keros), a reference to the characteristic odour of the raw mineral. Historically the wax was mined in significant quantities in Galicia around Boryslav in the Carpathians, and on Cheleken Island in the Caspian Sea, with commercial extraction organised by enterprises such as the Boryslaw Actien Gesellschaft and financed through institutions like the Galizische Kreditbank. The British petroleum chemist Boverton Redwood documented ozokerite mining and its refining in early technical literature. Mining later declined sharply as cheaper petroleum-derived waxes such as paraffin displaced the natural product, though deposits in Utah and elsewhere kept limited production alive.

Appearance and colour variations of ozokerite

Ozokerite is naturally coloured, and the depth of that colour tracks directly with its resin content. Low-resin grades appear yellow to light brown, while resin-rich material darkens through green and brown tones to nearly black. Medical ozokerite produced under the modern process is dark brown, with a specific gravity of 0.8–0.97.

How colour depends on resin content

The correlation between colour and resin content in ozokerite is close enough that appearance can serve as a rough field indicator of purity. As petroleum resins accumulate in the wax, the transitional shades deepen; refining that removes resins therefore lightens the product. This is why the purified ceresin derived from ozokerite is far paler than the dark raw mineral it comes from.

Physical properties of ozokerite

Ozokerite dissolves readily in many resins, gasoline, petroleum, benzene and chloroform, but is insoluble in water. It is blended in defined proportions with animal fats, vegetable oils and paraffin. Treating hot ozokerite with fuming sulphuric acid yields ceresin, a refined wax with valuable physical and chemical properties.

Specific gravity and solubility

The specific gravity of ozokerite falls between 0.8 and 0.97, and its solubility profile — soluble in hydrocarbon and chlorinated solvents, insoluble in water — makes it strongly hydrophobic. This water-repellent, film-forming behaviour underlies both its industrial uses as a moisture barrier and its occlusive role in skincare formulations.

Crystalline structure and consistency

Ozokerite has a fine-crystalline, needle-like structure, and this microstructure explains its ability to dissolve oils well and hold them firmly, producing a homogeneous, stable composition. Because the crystals form an interlocking network, ozokerite is an effective viscosity-controlling and structuring agent, gelling liquid oils into a coherent solid mass.

Melting point and its characteristics

The melting point of ozokerite is one of its two defining constants, and natural grades typically soften over a range roughly between 58 °C and 100 °C depending on origin and refining. Importantly, melting behaviour is measured separately from hardness: the two are not directly linked. A low-melting ozokerite can be just as hard as a high-melting one, so formulators specify both the drop-melting (congeal) point and penetration when selecting a grade. Standardised test methods such as ASTM D938 for congeal point and ASTM D3236 for viscosity are used commercially to characterise wax grades precisely.

Penetration as the primary indicator

The consistency of ozokerite depends on the amount of liquid hydrocarbons (oils) it contains and is quantified by penetration. This constant is independent of melting point — a low-melting ozokerite may match a high-melting one in hardness — and the consistency can range from soft and viscous to hard and brittle. Penetration is measured by needle methods analogous to ASTM D1321, giving formulators a reproducible number for hardness that guides blending and end-use selection.

Chemical composition of ozokerite

Chemical analysis of ozokerite shows it contains 84.4–86.1% carbon and 13.7–15.3% hydrogen, confirming its nature as a pure hydrocarbon mixture. On dry distillation the product yields gasoline at 3.67%, kerosene at 5.6–25.6%, paraffin at 56.8–82.3%, resin at about 2%, and gases and coke at around 6%.

Hydrocarbon structure and element content

Ozokerite is built almost entirely from long-chain saturated hydrocarbons of the paraffin series, which is why its carbon-to-hydrogen ratio sits so close to that of refined paraffin and petroleum-derived hydrocarbon waxes. The absence of reactive functional groups makes ozokerite chemically inert, stable in storage, and non-reactive with most cosmetic and pharmaceutical ingredients — a key reason it works well as an inert base.

Products of dry distillation of ozokerite

Dry distillation breaks ozokerite down into a series of familiar petroleum fractions, with paraffin making up the largest share at 56.8–82.3%, followed by kerosene, gasoline, resin and residual gases and coke. These derivatives illustrate how closely ozokerite is chemically related to crude oil and to the paraffin and mineral oils that are refined from it.

Component composition: ceresin, paraffin, resins

The component composition of ozokerite is as follows: ceresin 69–80%, paraffin 3–7%, mineral oils 1–2%, petroleum resins 8–10%, asphaltenes 0.5–5%, and mechanical impurities 3–8%. Ceresin thus dominates the wax, which is why refined ozokerite is often sold and described commercially under the ceresin name.

Ash analysis and mineral impurities

Analysis of the ash left after burning ozokerite reveals sulphur, iron, sodium, potassium and nitrogen. These trace mineral impurities come from the geological matrix in which the wax formed and are largely removed during purification, which is essential when the wax is destined for medical or cosmetic use where purity standards are strict.

Ceresin: production and applications

Ceresin is produced by acting on hot ozokerite with fuming sulphuric acid, a refining step that removes resins and impurities and yields a wax of superior physical and chemical properties. It has been established that ceresin can form a film on the surface of objects that is impermeable to water, gases, acids and alkalis, a property exploited across many branches of industry.

Technology of ceresin production from ozokerite

The conversion of ozokerite to ceresin relies on sulphuric acid treatment followed by filtration and bleaching, which lightens the dark raw wax and raises its melting range. Modern suppliers such as Koster Keunen offer refined grades — for example products marketed as Ozokerite Wax 70 — with controlled congeal points and penetration values suited to cosmetic manufacturing.

Protective and cosmetic properties of ceresin

Ceresin acts favourably on the skin and penetrates well into its surface layers, which is why the perfumery industry uses it to make creams. In practice, ceresin blended with sunflower oil or other oils can serve as a base for ointments and as an inert stand-alone remedy in the treatment of skin diseases. Its impermeable film also gives it occlusive properties, helping formulations retain skin moisture while resisting attack from water, acids and alkalis.

Medical ozokerite and its production technology

To make rational use of the waste from the oil-extraction and oil-refining industries, a decision was taken to build a shop for producing medical ozokerite at the Boryslav ozokerite mine administration in the town of Boryslav, Lviv region. After the necessary studies of the physicochemical indicators of the raw material, a defined component composition for medical ozokerite was approved.

Component composition of medical ozokerite

The approved raw components of medical ozokerite are paraffinic "cork", "poluika" (vein wax) and petrolatum. Blending these in controlled proportions produces a therapeutic wax with the consistent thermal behaviour required for medical heat treatment.

Technical conditions and quality standards

The medical ozokerite obtained conforms to the technical conditions of the Standards Committee, MRTU 12N-84-64. Samples of therapeutic ozokerite taken on 14 December 1967 are shown in Table 1.

Physicochemical indicators of medical ozokerite

Since the principal indicators characterising ozokerite should be considered the melting point and penetration (M. F. Sukharev, 1960), it is worth citing data on the melting point and other constants of the medical ozokerite produced in Boryslav; the study was carried out by the head of the laboratory, engineer L. Ya. Dokshtein, in 1967. These physicochemical checks confirm that a therapeutic grade meets defined water content, impurity and penetration limits before release.

Thermophysical characteristics of ozokerite

Given that medical ozokerite was obtained by a new technology, some of its thermophysical characteristics were studied together with O. V. Makarenko (1967) and compared with those of the previously used ozokerite; the comparative data are given in Table 2. As the table shows, there are no significant differences in the thermophysical indicators of ozokerite made by the new and the old technology, meaning the modern product delivers the same heat-retaining performance that makes ozokerite valued in thermotherapy.

Table 2 — Comparative characteristics of the thermophysical properties of ozokerite:

The low thermal conductivity combined with high heat capacity is precisely what makes ozokerite an effective medium for heat therapy: it stores warmth and releases it slowly, without causing burns at temperatures that would scald with water.

Uses of ozokerite in industry and medicine

Ozokerite and its refined derivative ceresin have a long history of industrial and pharmaceutical use, from electrical insulation to therapeutic heat packs. The waterproof, acid- and alkali-resistant film that ceresin forms made it valuable as an electrical insulator — the trade product Okonite and insulated boot materials both drew on this property — while shoemakers used ozokerite-based Heel-ball for finishing leather. Because ozokerite is chemically inert and holds oils firmly, it also appears in candles, crayons, coatings and polishes, and as an inert ointment base in medicine.

Use in cosmetics and perfumery

In cosmetics and personal care, ozokerite functions as a structuring and viscosity-controlling wax that gives stick and balm products their solid, spreadable form. It is widely used in lip balms, lip care sticks, foundation and makeup sticks, sunscreen sticks, and creams, where it binds oils, stabilises emulsions and imparts opacity. Brands and suppliers associated with such formulations include Clinique, Revlon, Blistex, Palmer's, ACO and specialty wax makers based in places like Watertown, Connecticut. Anyone interested in ingredient science alongside broader beauty topics will recognise ozokerite as a workhorse of the stick-product category.

Identifying ozokerite: CAS and EC numbers

Ozokerite is catalogued under standard chemical reference numbers that let regulators and formulators identify it unambiguously. In cosmetics it carries the INCI name Ozokerite, and refined petroleum-derived equivalents are listed under names such as Hydrocarbon Waxes (Petroleum). These identifiers appear in the European CosIng database and in industry resources like the COSMILE Europe ingredient database maintained under COSMETICS EUROPE, allowing consumers to look up an ingredient's function and safety status by its reference number.

Ozokerite in cosmetic formulations and its functions

Ozokerite performs several distinct roles in a cosmetic formula at once, which is why it is so common in solid products. Its primary functions are viscosity control, emulsion stabilisation, binding, opacifying and film formation, and its hydrophobic, occlusive nature helps limit water loss from the skin. Because it thickens oils into a firm yet workable mass, it is a natural choice wherever a product must hold its shape at room temperature but glide on when applied.

Binding function in cosmetic products

As a binder, ozokerite holds the oil and pigment phases of a stick together so the product does not crumble or bleed oil. This binding action is what allows lipsticks, foundation sticks and crayons to be moulded into a stable form, and it works alongside the wax's viscosity-controlling role to fine-tune hardness and payoff.

Safety and EU regulatory requirements

Ozokerite is a permitted cosmetic ingredient in the European Union, listed in CosIng and subject to REACH compliance for the substances placed on the market. Cosmetic-grade mineral hydrocarbons undergo safety assessment against purity standards such as USP 741 for melting range and pharmacopoeial limits on impurities, and bodies including the German Federal Institute for Risk Assessment (BfR) have evaluated refined mineral waxes and oils. Since 2013 the European Union has enforced a complete ban on animal testing for cosmetics, so ozokerite used in EU products meets cruelty-free requirements, and refined grades can also carry kosher certification where suppliers verify it.

Myths about mineral oils clogging pores

The claim that refined mineral waxes and oils clog pores or act as endocrine disruptors is not supported by the safety assessments of cosmetic-grade material. Highly purified mineral hydrocarbons used in cosmetics are inert, non-comedogenic at cosmetic use levels, and free of the aromatic contaminants found in crude fractions, which is exactly what the purity standards are designed to guarantee. Regulatory reviews distinguish sharply between crude industrial oils and the refined ozokerite and mineral oils permitted in personal care products.

Competition from petroleum-based products

Natural ozokerite has long competed with cheaper petroleum-derived waxes, and this competition drove the historical decline of ozokerite mining. As refineries learned to produce paraffin, microcrystalline waxes and synthetic ceresin substitutes at scale, the labour-intensive mining of natural earth wax in Galicia and elsewhere became uneconomic. Today much of the "ozokerite" and ceresin sold to industry is a refined petroleum product with the same functional properties, and formulators choose between natural and petroleum-based grades on cost, purity and supply rather than performance. For a broader look at how such raw materials feed into applied fields, see our coverage of medicine.

Related articles: Ozokerite therapy, Paraffin ozokerite

Reference: I. Yu. Goldenberg, "Ozokerite and Its Therapeutic Properties".