Vegetable tar: is a viscous liquid with a pungent and intense odor, blackish brown in color, obtained by dry distillation of the wood of some trees, such as birch, beech and pine. Norwegian tar, obtained by dry distillation of Norwegian pines, it is the most valuable.
Mineral tar: obtained from the distillation of bituminous coal (coal tar or mineral tar); it is a black, thick and viscous liquid. It has a stronger action than the previous one, but is also more irritating to the skin.
On the market there are numerous non-standard formulations based on tar (mineral or vegetable), so it is good to be guided in the choice directly by your doctor or by your trusted pharmacist / herbalist.
Vegetable tar is mainly used in dermatology, because it is an excellent disinfectant, antimicrobial and keratoplastic. Dry distillation allows the passage from the liquid state to the gaseous state of low molecular weight compounds, such as phenols, which undergo a reduction. Sometimes, vegetable tar is so rich in compounds
The fractional distillation of these compounds leads to the isolation of phenolic chemical classes, which can be used in other sectors. For example: from the fractional distillation of vegetable tar, guaiacol is obtained, a strong disinfectant used in dentistry; another compound obtained by fractional distillation of the tar is creosote (20% guaiacol), a phenolic fraction used as a disinfectant in healthcare.
Property
Tar has keratoplastic properties for which, once applied locally, it determines, with an unknown mechanism, a reduction in the number and size of epidermal cells. It also has an anti-itch and anti-irritant action.
Tar has also been incorporated into shampoos, used for seborrheic dermatitis, hair psoriasis and dandruff.
Shampoo al vegetable tar against dandruff: applied to wet hair, it should be made to foam and left to act for a few minutes. Its tolerability must be tested; if its action is too intense to use it every day, it should be used alternating it with a mild shampoo.
Shampoos and lotions based on mineral tar (also in association with 1% salicylic acid) are used - under medical advice - to combat scalp psoriasis, while the direct application of 3-5% mineral tar-based lotions or ointments on skin rashes is indicated for skin psoriasis. Due to its photosensitizing action, mineral charcoal is often used to enhance the therapeutic action of UV light in the treatment of psoriasis.
- Properties: antipruritic, keratoplastic and mild antiseptic. Good antibacterial, resolving, balsamic and parasiticidal activity due to the high phenolic content
- Indications: Psoriasis (in this case the use of mineral tar is preferred), Forfoa, Chronic Eczema
Side and unwanted effects
Tar shampoos can make hair a little darker, especially those that are particularly light (blond or white). Even the smell is generally unwelcome by the user, as well as the stickiness that makes it difficult to remove, staining clothing and bed sheets.
Tar is a photosensitizing substance and as such makes the skin more sensitive to the sun, increasing the risk of chalking.
Tar should never be applied to broken or open skin. On sensitive skin or in case of excessive use it can cause side effects such as skin irritation (contact dermatitis), acneiform eruptions, formation of comedones, photosensitization, hypersensitivity reactions and folliculitis. It is therefore important that tar is used in adequate concentrations (not exceeding 2%) and incorporated in non-occlusive vehicles. For example, there are tar based products in gel and at low concentrations, cosmetically more acceptable because they do not stink, they can be used every day and wash off easily.Tar is generally contraindicated in case of easily irritated skin or in the course of acute rashes.
Other articles on "Tar - Vegetable Tar and Mineral Tar"
- Salicine
- Pharmacognosy
- Tannins
