L' ho letto su un presunto forum tipo questo ( che coraggio imitarci :D ) ....E' vero???Spero di no...mi cadrebbe il mito del mio olio di germe di grano :(
Ps : Un' erborista , che non possedeva l' olio di mandorle naturale , è riuscita a dire che gli olii puri fanno male , perchè seccano la pelle ......non ho parole ......o è vero? :O
Olii x il corpo comedogeni??????
Moderatore: Erica Congiu
Se vai a questo topic
viewtopic.php?t=12016&highlight=olio+comedogenicit%E0
trovi una tabella contenenete dei parametri sugli effetti comedogenici di oli naturali.
Penso comunque che dipenda dal tipo di pelle: io è da poco che mi sto dando al bioeco, ho sempre letto che il burro di karitè è un toccasana per tutti e cosa scopro? Che io non posso metterlo perché mi riempio di foruncoli :-( ... peccato perché mi lasciava la pelle davvero morbidissima ed elastica. A nessuno è mai capitato? E comunque anche l'olio di mandorle non posso metterlo per lo stesso problema.
viewtopic.php?t=12016&highlight=olio+comedogenicit%E0
trovi una tabella contenenete dei parametri sugli effetti comedogenici di oli naturali.
Penso comunque che dipenda dal tipo di pelle: io è da poco che mi sto dando al bioeco, ho sempre letto che il burro di karitè è un toccasana per tutti e cosa scopro? Che io non posso metterlo perché mi riempio di foruncoli :-( ... peccato perché mi lasciava la pelle davvero morbidissima ed elastica. A nessuno è mai capitato? E comunque anche l'olio di mandorle non posso metterlo per lo stesso problema.
Ciao Landre, se usi da un bel po' l'olio di germe di grano e non ti sei riempito di brufoli e punti neri vuol dire che per te è ok; infatti il problema se c'è si presenta quasi subito.
Certo che puoi bertelo l'olio, lo puoi usare anche per condire zuppe e insalate. Le perle possono risultare più comode per chi ne fa uso sporadico, così l'olio non irrancidisce.
Certo che puoi bertelo l'olio, lo puoi usare anche per condire zuppe e insalate. Le perle possono risultare più comode per chi ne fa uso sporadico, così l'olio non irrancidisce.
La formazione del comedone è un fenomeno complesso, tra l'altro legato a risposte soggettive della pelle.
A parità di sostanza, pelli diverse tendono ad avere risposte diverse.
L'articolo citato da PortoPietro citava ricerche collegate essenzialmente a meccansmi di irritabilità della pelle....in questo caso gli oli vegetali con molti polinsaturi o con alta acidità, possono essere a rischio.
La tesi, che non a caso assolveva gli occlusivi petroliferi e siliconici , è stata successivamente smontata da Kligman ( a memoria ) e altri dermatologi... così come la validità e confidenza del test nelle orecchie dei conigli, su cui si basava la ricerca pubblicata da C&T si è rivelata minima rispetto ai test su volontari umani.
Peraltro molti test succesivi di oli vegetali ricchi di polinsaturi hanno smentito le tesi di Lanzet.( a parità di test, quindi sempre rabbit ear test )
Il problema è veramente complesso e un po' nel forum se ne è parlato.
A titolo di esempio: ( Vittorio non incavolarti ) che senso ha l'analisi della comedogenicità di un prodotto quando alcune reazioni ( metabolismo dei grassi eudermici ) sono legate ad enzimi sviluppati dal corine bacteri... ???
Incollo l'articolo "incriminato" ed invito esperti e non a sbilanciarsi con opinioni ...
.....
The modern day skin treatment therapist should be aware of all cosmetic formulation side effects, it there are any. This will be a series of articles covering cosmetic formulation side effects
The realization that certain products, including cosmetics where responsible for causing acne-like effects became apparent during and after the Second World War, when it was found that people working with polychlorinated hydrocarbons developed comedones similar to those found in acne.
In 1956, Scientists developed a testing procedure using rabbits ears to study the effects of these chlorinated compounds. Further testing in 1968 showed that human sebum applied to the external ear of the rabbit resulted in comedones. This discovery led to the implication in 1972 that the rabbit ear was a useful model for testing cosmetics and raw materials for comedogenic activity. This induced acne-like condition became known as "acne cosmetica", and became the benchmark of significant exploration of this test procedure by several of the larger cosmetic companies at the time.
As research continued, studies proved that persistent eruption of acne-like comedones occurred in over 30% of adult women. This was attributed to certain base materials present in the cosmetics, such as isopropyl myristate. Half of the facial cosmetic products tested at the time, were found to be at least mildly comedogenic in the "rabbit ear test".
The "rabbit ear test" produced a measurable scale of comedogenicity, ranging from 1 to 5. In this manual the same five point grading scale will be used to demonstrate the comedogenic effects of various cosmetic raw ingredients commonly used today.
Grades 1 to 2 are considered non-to mildly comedogenic and grades 3 to 5 are considered significantly comedogenic. The ingredient score is displayed as a score out of 3 or 4. Example: 1/3, 2/3, 3/3, 3/4etc. When the score shown is 3/3, or 4/4, this means that the test ingredient produced a maximum score against the reference maximum.
Variations on concentrations affected the results of the tests, but certain strongly comedogenic materials remained severely irritating even when diluted to 5 and 10 %.
Products with high concentrations of any of the substances with a rating of 1/3 or more should be avoided with acne prone skins. Concentrations of substances with a rating of 2/3 - 3/4 should be avoided on any other than severely lipid dry skins, as they are severely comedogenic.
It is not uncommon for the composition of products to change although the brand name remains the same. Therapists must be ever vigilant.
The substances in the following tables are commonly found in cosmetic products manufactured worldwide. They have been grouped together in chemical types for ease of comparison. It is not uncommon for several of these substances to be found in the one product.
The Comedogenicity test results used in this article were sourced from a scientific paper written by Monroe Lanzet, a cosmetic chemist from Lanzet Associates of California, USA. They are the correlation of data from several independent cosmetic manufacturers in the US.
Table 1: Isopropyl Esters
Isopropyl esters are widely used in cosmetics to produce a light, non-greasy, emollient that feels good on the skin. They are manufactured from various compounds including edible fats, oils and lanolin derivatives.
They are normally quite comedogenic when undiluted, but when used in concentrations of 5%, are safely used as part of an otherwise non-comedogenic oil phase with no comedogenic effects.
Table 1: Isopropyl Esters
Isopropyl linoleate
Isopropyl myristate
Isopropyl palmitate
Isopropyl lanolate
Isopropyl isostearate
Di isopropyl adipate
Results
3/3
3/3
2/3
3/3
3/3
0/3
Non-comedogenic ingredients
None of the silicones commonly used as a base in ointments and skin protectants tested as comedogenic. (see table 2)
Table 2: Silicones
Dimethicone
Dimethicone copolyol
Silicone wax, 10% in dimethicone
Stearoxy dimethicone, 10% in dimethicone
Cyclomethicone
Results
0/4
0/4
0/4
0/4
0/4
Table 3:Surfactants & pigments
The emulsifier and surfactant sodium lauryl sulphate, although non-comedogenic, shows conflicting results possibly from it's high degree of irritancy. It appears comedogenic, but it's true irritation effect manifests as excessive keratosis, hypokeratosis or ulceration.
It may also cause skin drying because of it's degreasing ability, and is found most commonly in emollient creams, cream depilatories, shampoos and hand lotions.
The common water-soluble cosmetic pigments shown on table 3 also tested non-comedogenic.
Table 3:Surfactants & pigments
Sodium lauryl sulphate, 5% in water.
Sodium lauryl sulphate 1% in water
Iron oxides, 25% in propylene glycol
Titanium dioxide, 25% in propylene glycol
Results
3/4
2/3
0/4
0/4
Table 4: Hydrocarbons
Because of the properties of hydrocarbons, they are used in the cosmetic industry quite extensively as lubricants in lipsticks and in creams, as it helps make them smoother and shiny. The oily film of hydrocarbon based ingredient helps to prevent evaporation of moisture, in addition to helping soften and smooth the skin in the same way as any other emollients. They are often used in preference to other ingredients because they are less expensive.
Table 4: Hydrocarbons
Petroleum Distillate
Polyethylene, 50% in mineral oil
Polybutene
Petrolatum
Mineral Oil, light
Isoparaffin c8-9
Isoparaffin C9-11
Isoparaffin C11-13
Isoparaffin C13-16
Squalene
Results
1/3
0/3
0/3
1/3
1/3
0/3
1-2/3
0/3
2/3
1/3
The level of refinement of the base ingredient would dictate the level of contamination, and the quantity used in the cosmetic would be an aggravating factor in the comedogenicity of the final product.
Mineral oil and petrolatum are shown to be mildly comedogenic, as are most high refinement petroleum products. However, some others are more comedogenic, this may be due to contamination. Both mineral oil and petrolatum are shown comedogenic because of their occlusive properties when used on incorrect skin conditions.
Table 5: Oleic/ Oleyl & alcohol
Both oleic acids and oleyl alcohol are extremely comedogenic. They are used in preference to full weight vegetable oils because of their superior skin penetrating properties.
They are derived from either animal, fish or vegetable oil sources and are used in cold creams, nail polish, toilet soaps and liquid make-ups.
Table 5: Oleic/Oleyl & alcohol
Oleic acid
Oleyl alcohol, 50% in propylene glycol
Oleyl alcohol, 10% in propylene glycol
Decyl oleate
Isodecyl oleate
Oleth-2, 2% in propylene glycol
Results
3/3
3/3
2-3/3
2/3
1/3
1/4
Table 5 also shows that dilution of oleyl alcohol within a non-comedogenic carrier substance such as propylene glycol will not significantly reduce the comedogenic effect.
The severity of comedogenic reactions from oleic acid may be moderated in some formulations by glycerin, a non-comedogenic substance commonly used as a solvent, humectant or emollient. As shown below, certain saturated acids and alcohol used as cosmetic lubricants and emollients have comedogenic potential.
Table 6: Sorbitan / Methyl Glucose
Sorbitans are generally found as emulsifiers and stabilisers in creams and lotions, and are insoluble in water. Sorbitan oleate is less comedogenic than oleic acid and sorbitan sesquioleate is non-comedogenic. Oleic acids, when combined with sorbitan, reduce potential comedogenic effects. Similarly, Methyl glucose sesquistearate when combined with sorbitan, decyl or isodecyl, reduces comedogenic effects, but when used in combination with isopropyl alcohol or propylene glycol, may enhance comedogenicity.
Table 6:
Sorbitan laurate
Sorbitan oleate
Sorbitan.sesquioleate
Polysorbate-60
Polysorbate-80
Methyl.gluceth.sesquistearate
Methyl.glucose.sesquistearate.10%
in propylene glycol
Results
0/3
2/3
0/3
0/3
0/3
0/3
1/3
Table 7:Effects of physical dilution
The real severity of comedogenic response is best demonstrated by dilution. In table 7 octyl palmitate, a typical ingredient in sunscreens, scores 3/3, as does oleyl alcohol (see table 5). The comedogenecy of octyl palmitate is reduced to 1/3 at 50% dilution, and 0/3 at 5%. Oleyl alcohol when similarly diluted remains 3/3 at 50% and is still 2/3 at 10%.
Conclusions from this comparison indicate that oleyl alcohol is a far more comedogenic substance than octyl palmitate. People with acne prone skin conditions should therefore avoid products containing oleyl alcohol. They may however, tolerate small to moderate concentrations of octyl palmitate without adverse effects.
The emollient Isopropyl myristate, which scores 3/3 (see table 1) shows similar dilution characteristics as oleyl alcohol.
Table7: Octyl Palmitate in Dilution
Octyl Palmitate, 100%
Octyl palmitate, 50%
Octyl palmitate, 5%
Results
1 /3
1/3
0/3
Table 8: Lactates
Myristyl lactate is a relatively severe comedogenic ingredient used commonly in moisturisers and sunscreens. Its dilution to 50% in a propylene glycol base will not reduce its comedogenic score. However, when combined with cetyl alcohol, the severity of any reaction is significantly reduced.
Table 8: Lactates
Myristyl lactate 100%
Myristyl lactate, 50% in propylene glycol
Myristyl lactate, 50% in cetyl alcohol
Results
2-3/3, 3/4
2-3/3
0-1/4
Table 9: Effects of Un-saturation on Comedogenicity
A relatively large number of vegetable oils used as emollients in moisturisers, soaps, cleansers and sunscreens, were found to show comedogenic effects ranging from 0/3 to 3/3. This is an alarming and embarrassing discovery for the Beauty Therapy industry, as many of these vegetable oils have been used as carriers in aromatherapy and massage oils for many years. With this in mind, it is now obvious why beauty therapy students often complain that their skins were just fine until they started their training.
Saturated triglycerides are generally far less comedogenic than unsaturated oils (avocado oil is an exception), and sunflower seed oil is far less comedogenic that sweet almond or grape seed oil.
Table 9: Fats and Oils
Capric/caprylic triglyceride
Hydrogenated vegetable oil
Coconut oil
Hydrogenated lard glyceride
Avocado oil
Castor oil
Peanut oil
Hybrid safflower oil
Peach kernel oil
Sweet almond oil
Grape seed oil
Sunflower seed oil
Results
2/4
1/3
2/3
0/3
0/3
0/3
1/3
1-2/3
2-3/3
3/3
2-3/3
1/3
Table 10: Glycols and Glycol Esters
Glycols are water-soluble substances commonly used in cosmetics as humectants. Table 10 shows the moderating effect of the noncomedogenic substances glycerin and propylene glycol. As a good rule of thumb, water-soluble materials are generally minimally comedogenic. Glycerol and glycol stearates are minimally comedogenic, but are not moderated by dilution in propylene glycol. Glyceryl oleate, by virtue of it's severely comedogenic cousin, decaglyceryl decaoleate, is probably at least moderately comedogenic. No data was available on glyceryl oleate itself, but the conclusion that it is comedogenic is drawn from the fats and oils studied in table 9.
Propylene glycol tends to prevent comedogenicity by modifying the molecular structure and chemically diluting any comedogenic elements.
Table 10: Glycol and Glycol Esters
Glycerin
Glyceryl stearate
Glyceryl stearate, 30% in propylene glycol
Glyceryl stearate, 10% in propylene glycol.
Decaglyceryl decaoleate
Glyceryl triacetyl ricinoleate
Propylene glycol
Propylene glycol stearate
Propylene glycol decaprylate/dicaprate
Glycol stearate, 10% in propylene glycol
Results
0/3
0-1/3
0-1/3
0-1/3
2-3/3
0/3
0/3
1/3
0/3
0-1/3
Table 11: Lanolin and Lanolin Derivatives
Lanolin is a mildly comedogenic substance found in a variety of cosmetic products. Considered a wax rather than fat, an essential component of lanolin is cholesterol. Lanolin oil is a fluid fraction of lanolin and, as expected, has the same minimal score as lanolin.
Lanolin alcohols, of which cholesterol is the best known, is also minimally comedogenic and is noncomedogenic when, diluted to 10% or less.
The offending comedogenic element of lanolin is lanolic acid. Dilution of lanolic acid to 10% in corn oil does not lessen its severity. Derivatives of lanolic acid, such as isopropyl lanolate, and hydrogenated lanolin, also contain lanolin acids, and are similarly comedogenic.
Table 11: Lanolin and Lanolin Derivatives
Lanolin
Lanolin Oil
Lanolin alcohol, 100%
Lanolin alcohol, 10 % in mineral oil
Cholesterol
Lanolic acid
Lanolic acid, 10% in corn oil
Isopropyl lanolate
Hydrogenated lanolin
Acetylated lanolin alcohol
Laneth-5
Laneth-20
Laneth-10 acetate
Results
0-1/3
0-1/3
1/3
1/3
0/3
3/3
3/3
2-3/3
2/3
2-3/3
1/3
0/3
2/4-1/3
Table 12/13/14: Fatty Alcohols and Fatty Acids
This group of substances is derived from a multitude of sources including fish, animals and plants. Myristyl, cetyl and stearyl alcohols are noncomedogenic, but unsaturated alcohol such as oleyl, isostearyl and octyl dodecanol are moderately to severely comedogenic. Hexadecyl alcohol is also known to be severely comedogenic.
The acids in this group are more comedogenic than the equivalent alcohols. Stearyl alcohol is minimally comedogenic while stearic acid scored higher. Isostearic acid must be considered severely comedogenic because of the high score even at 10% dilution in propylene glycol.
Table 12: Fatty Alcohols
Lauryl alcohol, 50% in mineral oil
Myristyl alcohol, 50% in mineral oil
Cetyl alcohol
Stearyl alcohol
Oleyl alcohol, 50% in propylene glycol
Oleyl alcohol, 10% in propylene glycol
Isostearyl alcohol
Isostearyl alcohol, 10% in mineral oil
Octyl dodecanol
Results
1/3
0/3
0/3
0/3
3/3
2-3/3
3/3
2/3
2/3
Table 13: Fatty Acids
Stearic acid 1/3
Stearic acid, 50% in mineral oil 1/3
Oleic acid 3/3
Isostearic acid, 50% in propylene glycol 3/3
Isostearic acid, 10% in propylene glycol 2-3/3
Results
1/3
1/3
3/3
3/3
2-3/3
Table 14: Alcohols, Glycols and Polyglycols
Glycerin
PEG 200
PEG 300
PEG 8
Butylene glycol
Propylene glycol
Hexylene glycol
Benzyl alcohol
Ethyl hexane diol
Polypropylene glycol 15-200
Results
0/3
0/3
0/3
0/3
0-1/3
0/3
2/3
0/3
0/3
0/3
Table 15: Assorted Esters and Ethers
Both esters and ethers are derived from alcohol’s and used in the manufacture of emollients. Used to improve the feel or humectant qualities of cosmetics, they have been found to be mildly to severely comedogenic. Many are commonly used as moisture carrying vehicles instead of water, and although giving better permeation through the skin, they are often linked to sensitivity reactions.
Those listed below are commonly used in the industry. As shown, even when diluted with propylene glycol they show very small changes in the comedogenicity.
Butyl stearate and oleyl alcohol are in the extra severe class, promoting comedogenicity on minimally comedogenic substances even when diluted down to concentrations of 5%.
Cosmetics containing these materials should be avoided by people with oily or acne prone skins.
Table 15: Esters and Ethers
Triethyl citrate, water soluble
PPG 2 myristyl propionate
Myristyl myristate
Myristyl propionate
Myreth 3 myristate, 50% in propylene glycol
Myreth 3 myristate, 10% in propylene glycol
PPG 15 stearyl ether
Isocetyl stearate
C12-C15 alcohols benzoate
Butyl stearate, 100%
Butyl stearate, 5% in mineral oil
Isostearyl neopentanoate
Isodecyl isononanate 15-200
Results
0/3
0/3
2/3
2/3
3/3
2-3/3
2/2
0/3
3/3
2/3
1/3
0/3
A parità di sostanza, pelli diverse tendono ad avere risposte diverse.
L'articolo citato da PortoPietro citava ricerche collegate essenzialmente a meccansmi di irritabilità della pelle....in questo caso gli oli vegetali con molti polinsaturi o con alta acidità, possono essere a rischio.
La tesi, che non a caso assolveva gli occlusivi petroliferi e siliconici , è stata successivamente smontata da Kligman ( a memoria ) e altri dermatologi... così come la validità e confidenza del test nelle orecchie dei conigli, su cui si basava la ricerca pubblicata da C&T si è rivelata minima rispetto ai test su volontari umani.
Peraltro molti test succesivi di oli vegetali ricchi di polinsaturi hanno smentito le tesi di Lanzet.( a parità di test, quindi sempre rabbit ear test )
Il problema è veramente complesso e un po' nel forum se ne è parlato.
A titolo di esempio: ( Vittorio non incavolarti ) che senso ha l'analisi della comedogenicità di un prodotto quando alcune reazioni ( metabolismo dei grassi eudermici ) sono legate ad enzimi sviluppati dal corine bacteri... ???
Incollo l'articolo "incriminato" ed invito esperti e non a sbilanciarsi con opinioni ...
.....
The modern day skin treatment therapist should be aware of all cosmetic formulation side effects, it there are any. This will be a series of articles covering cosmetic formulation side effects
The realization that certain products, including cosmetics where responsible for causing acne-like effects became apparent during and after the Second World War, when it was found that people working with polychlorinated hydrocarbons developed comedones similar to those found in acne.
In 1956, Scientists developed a testing procedure using rabbits ears to study the effects of these chlorinated compounds. Further testing in 1968 showed that human sebum applied to the external ear of the rabbit resulted in comedones. This discovery led to the implication in 1972 that the rabbit ear was a useful model for testing cosmetics and raw materials for comedogenic activity. This induced acne-like condition became known as "acne cosmetica", and became the benchmark of significant exploration of this test procedure by several of the larger cosmetic companies at the time.
As research continued, studies proved that persistent eruption of acne-like comedones occurred in over 30% of adult women. This was attributed to certain base materials present in the cosmetics, such as isopropyl myristate. Half of the facial cosmetic products tested at the time, were found to be at least mildly comedogenic in the "rabbit ear test".
The "rabbit ear test" produced a measurable scale of comedogenicity, ranging from 1 to 5. In this manual the same five point grading scale will be used to demonstrate the comedogenic effects of various cosmetic raw ingredients commonly used today.
Grades 1 to 2 are considered non-to mildly comedogenic and grades 3 to 5 are considered significantly comedogenic. The ingredient score is displayed as a score out of 3 or 4. Example: 1/3, 2/3, 3/3, 3/4etc. When the score shown is 3/3, or 4/4, this means that the test ingredient produced a maximum score against the reference maximum.
Variations on concentrations affected the results of the tests, but certain strongly comedogenic materials remained severely irritating even when diluted to 5 and 10 %.
Products with high concentrations of any of the substances with a rating of 1/3 or more should be avoided with acne prone skins. Concentrations of substances with a rating of 2/3 - 3/4 should be avoided on any other than severely lipid dry skins, as they are severely comedogenic.
It is not uncommon for the composition of products to change although the brand name remains the same. Therapists must be ever vigilant.
The substances in the following tables are commonly found in cosmetic products manufactured worldwide. They have been grouped together in chemical types for ease of comparison. It is not uncommon for several of these substances to be found in the one product.
The Comedogenicity test results used in this article were sourced from a scientific paper written by Monroe Lanzet, a cosmetic chemist from Lanzet Associates of California, USA. They are the correlation of data from several independent cosmetic manufacturers in the US.
Table 1: Isopropyl Esters
Isopropyl esters are widely used in cosmetics to produce a light, non-greasy, emollient that feels good on the skin. They are manufactured from various compounds including edible fats, oils and lanolin derivatives.
They are normally quite comedogenic when undiluted, but when used in concentrations of 5%, are safely used as part of an otherwise non-comedogenic oil phase with no comedogenic effects.
Table 1: Isopropyl Esters
Isopropyl linoleate
Isopropyl myristate
Isopropyl palmitate
Isopropyl lanolate
Isopropyl isostearate
Di isopropyl adipate
Results
3/3
3/3
2/3
3/3
3/3
0/3
Non-comedogenic ingredients
None of the silicones commonly used as a base in ointments and skin protectants tested as comedogenic. (see table 2)
Table 2: Silicones
Dimethicone
Dimethicone copolyol
Silicone wax, 10% in dimethicone
Stearoxy dimethicone, 10% in dimethicone
Cyclomethicone
Results
0/4
0/4
0/4
0/4
0/4
Table 3:Surfactants & pigments
The emulsifier and surfactant sodium lauryl sulphate, although non-comedogenic, shows conflicting results possibly from it's high degree of irritancy. It appears comedogenic, but it's true irritation effect manifests as excessive keratosis, hypokeratosis or ulceration.
It may also cause skin drying because of it's degreasing ability, and is found most commonly in emollient creams, cream depilatories, shampoos and hand lotions.
The common water-soluble cosmetic pigments shown on table 3 also tested non-comedogenic.
Table 3:Surfactants & pigments
Sodium lauryl sulphate, 5% in water.
Sodium lauryl sulphate 1% in water
Iron oxides, 25% in propylene glycol
Titanium dioxide, 25% in propylene glycol
Results
3/4
2/3
0/4
0/4
Table 4: Hydrocarbons
Because of the properties of hydrocarbons, they are used in the cosmetic industry quite extensively as lubricants in lipsticks and in creams, as it helps make them smoother and shiny. The oily film of hydrocarbon based ingredient helps to prevent evaporation of moisture, in addition to helping soften and smooth the skin in the same way as any other emollients. They are often used in preference to other ingredients because they are less expensive.
Table 4: Hydrocarbons
Petroleum Distillate
Polyethylene, 50% in mineral oil
Polybutene
Petrolatum
Mineral Oil, light
Isoparaffin c8-9
Isoparaffin C9-11
Isoparaffin C11-13
Isoparaffin C13-16
Squalene
Results
1/3
0/3
0/3
1/3
1/3
0/3
1-2/3
0/3
2/3
1/3
The level of refinement of the base ingredient would dictate the level of contamination, and the quantity used in the cosmetic would be an aggravating factor in the comedogenicity of the final product.
Mineral oil and petrolatum are shown to be mildly comedogenic, as are most high refinement petroleum products. However, some others are more comedogenic, this may be due to contamination. Both mineral oil and petrolatum are shown comedogenic because of their occlusive properties when used on incorrect skin conditions.
Table 5: Oleic/ Oleyl & alcohol
Both oleic acids and oleyl alcohol are extremely comedogenic. They are used in preference to full weight vegetable oils because of their superior skin penetrating properties.
They are derived from either animal, fish or vegetable oil sources and are used in cold creams, nail polish, toilet soaps and liquid make-ups.
Table 5: Oleic/Oleyl & alcohol
Oleic acid
Oleyl alcohol, 50% in propylene glycol
Oleyl alcohol, 10% in propylene glycol
Decyl oleate
Isodecyl oleate
Oleth-2, 2% in propylene glycol
Results
3/3
3/3
2-3/3
2/3
1/3
1/4
Table 5 also shows that dilution of oleyl alcohol within a non-comedogenic carrier substance such as propylene glycol will not significantly reduce the comedogenic effect.
The severity of comedogenic reactions from oleic acid may be moderated in some formulations by glycerin, a non-comedogenic substance commonly used as a solvent, humectant or emollient. As shown below, certain saturated acids and alcohol used as cosmetic lubricants and emollients have comedogenic potential.
Table 6: Sorbitan / Methyl Glucose
Sorbitans are generally found as emulsifiers and stabilisers in creams and lotions, and are insoluble in water. Sorbitan oleate is less comedogenic than oleic acid and sorbitan sesquioleate is non-comedogenic. Oleic acids, when combined with sorbitan, reduce potential comedogenic effects. Similarly, Methyl glucose sesquistearate when combined with sorbitan, decyl or isodecyl, reduces comedogenic effects, but when used in combination with isopropyl alcohol or propylene glycol, may enhance comedogenicity.
Table 6:
Sorbitan laurate
Sorbitan oleate
Sorbitan.sesquioleate
Polysorbate-60
Polysorbate-80
Methyl.gluceth.sesquistearate
Methyl.glucose.sesquistearate.10%
in propylene glycol
Results
0/3
2/3
0/3
0/3
0/3
0/3
1/3
Table 7:Effects of physical dilution
The real severity of comedogenic response is best demonstrated by dilution. In table 7 octyl palmitate, a typical ingredient in sunscreens, scores 3/3, as does oleyl alcohol (see table 5). The comedogenecy of octyl palmitate is reduced to 1/3 at 50% dilution, and 0/3 at 5%. Oleyl alcohol when similarly diluted remains 3/3 at 50% and is still 2/3 at 10%.
Conclusions from this comparison indicate that oleyl alcohol is a far more comedogenic substance than octyl palmitate. People with acne prone skin conditions should therefore avoid products containing oleyl alcohol. They may however, tolerate small to moderate concentrations of octyl palmitate without adverse effects.
The emollient Isopropyl myristate, which scores 3/3 (see table 1) shows similar dilution characteristics as oleyl alcohol.
Table7: Octyl Palmitate in Dilution
Octyl Palmitate, 100%
Octyl palmitate, 50%
Octyl palmitate, 5%
Results
1 /3
1/3
0/3
Table 8: Lactates
Myristyl lactate is a relatively severe comedogenic ingredient used commonly in moisturisers and sunscreens. Its dilution to 50% in a propylene glycol base will not reduce its comedogenic score. However, when combined with cetyl alcohol, the severity of any reaction is significantly reduced.
Table 8: Lactates
Myristyl lactate 100%
Myristyl lactate, 50% in propylene glycol
Myristyl lactate, 50% in cetyl alcohol
Results
2-3/3, 3/4
2-3/3
0-1/4
Table 9: Effects of Un-saturation on Comedogenicity
A relatively large number of vegetable oils used as emollients in moisturisers, soaps, cleansers and sunscreens, were found to show comedogenic effects ranging from 0/3 to 3/3. This is an alarming and embarrassing discovery for the Beauty Therapy industry, as many of these vegetable oils have been used as carriers in aromatherapy and massage oils for many years. With this in mind, it is now obvious why beauty therapy students often complain that their skins were just fine until they started their training.
Saturated triglycerides are generally far less comedogenic than unsaturated oils (avocado oil is an exception), and sunflower seed oil is far less comedogenic that sweet almond or grape seed oil.
Table 9: Fats and Oils
Capric/caprylic triglyceride
Hydrogenated vegetable oil
Coconut oil
Hydrogenated lard glyceride
Avocado oil
Castor oil
Peanut oil
Hybrid safflower oil
Peach kernel oil
Sweet almond oil
Grape seed oil
Sunflower seed oil
Results
2/4
1/3
2/3
0/3
0/3
0/3
1/3
1-2/3
2-3/3
3/3
2-3/3
1/3
Table 10: Glycols and Glycol Esters
Glycols are water-soluble substances commonly used in cosmetics as humectants. Table 10 shows the moderating effect of the noncomedogenic substances glycerin and propylene glycol. As a good rule of thumb, water-soluble materials are generally minimally comedogenic. Glycerol and glycol stearates are minimally comedogenic, but are not moderated by dilution in propylene glycol. Glyceryl oleate, by virtue of it's severely comedogenic cousin, decaglyceryl decaoleate, is probably at least moderately comedogenic. No data was available on glyceryl oleate itself, but the conclusion that it is comedogenic is drawn from the fats and oils studied in table 9.
Propylene glycol tends to prevent comedogenicity by modifying the molecular structure and chemically diluting any comedogenic elements.
Table 10: Glycol and Glycol Esters
Glycerin
Glyceryl stearate
Glyceryl stearate, 30% in propylene glycol
Glyceryl stearate, 10% in propylene glycol.
Decaglyceryl decaoleate
Glyceryl triacetyl ricinoleate
Propylene glycol
Propylene glycol stearate
Propylene glycol decaprylate/dicaprate
Glycol stearate, 10% in propylene glycol
Results
0/3
0-1/3
0-1/3
0-1/3
2-3/3
0/3
0/3
1/3
0/3
0-1/3
Table 11: Lanolin and Lanolin Derivatives
Lanolin is a mildly comedogenic substance found in a variety of cosmetic products. Considered a wax rather than fat, an essential component of lanolin is cholesterol. Lanolin oil is a fluid fraction of lanolin and, as expected, has the same minimal score as lanolin.
Lanolin alcohols, of which cholesterol is the best known, is also minimally comedogenic and is noncomedogenic when, diluted to 10% or less.
The offending comedogenic element of lanolin is lanolic acid. Dilution of lanolic acid to 10% in corn oil does not lessen its severity. Derivatives of lanolic acid, such as isopropyl lanolate, and hydrogenated lanolin, also contain lanolin acids, and are similarly comedogenic.
Table 11: Lanolin and Lanolin Derivatives
Lanolin
Lanolin Oil
Lanolin alcohol, 100%
Lanolin alcohol, 10 % in mineral oil
Cholesterol
Lanolic acid
Lanolic acid, 10% in corn oil
Isopropyl lanolate
Hydrogenated lanolin
Acetylated lanolin alcohol
Laneth-5
Laneth-20
Laneth-10 acetate
Results
0-1/3
0-1/3
1/3
1/3
0/3
3/3
3/3
2-3/3
2/3
2-3/3
1/3
0/3
2/4-1/3
Table 12/13/14: Fatty Alcohols and Fatty Acids
This group of substances is derived from a multitude of sources including fish, animals and plants. Myristyl, cetyl and stearyl alcohols are noncomedogenic, but unsaturated alcohol such as oleyl, isostearyl and octyl dodecanol are moderately to severely comedogenic. Hexadecyl alcohol is also known to be severely comedogenic.
The acids in this group are more comedogenic than the equivalent alcohols. Stearyl alcohol is minimally comedogenic while stearic acid scored higher. Isostearic acid must be considered severely comedogenic because of the high score even at 10% dilution in propylene glycol.
Table 12: Fatty Alcohols
Lauryl alcohol, 50% in mineral oil
Myristyl alcohol, 50% in mineral oil
Cetyl alcohol
Stearyl alcohol
Oleyl alcohol, 50% in propylene glycol
Oleyl alcohol, 10% in propylene glycol
Isostearyl alcohol
Isostearyl alcohol, 10% in mineral oil
Octyl dodecanol
Results
1/3
0/3
0/3
0/3
3/3
2-3/3
3/3
2/3
2/3
Table 13: Fatty Acids
Stearic acid 1/3
Stearic acid, 50% in mineral oil 1/3
Oleic acid 3/3
Isostearic acid, 50% in propylene glycol 3/3
Isostearic acid, 10% in propylene glycol 2-3/3
Results
1/3
1/3
3/3
3/3
2-3/3
Table 14: Alcohols, Glycols and Polyglycols
Glycerin
PEG 200
PEG 300
PEG 8
Butylene glycol
Propylene glycol
Hexylene glycol
Benzyl alcohol
Ethyl hexane diol
Polypropylene glycol 15-200
Results
0/3
0/3
0/3
0/3
0-1/3
0/3
2/3
0/3
0/3
0/3
Table 15: Assorted Esters and Ethers
Both esters and ethers are derived from alcohol’s and used in the manufacture of emollients. Used to improve the feel or humectant qualities of cosmetics, they have been found to be mildly to severely comedogenic. Many are commonly used as moisture carrying vehicles instead of water, and although giving better permeation through the skin, they are often linked to sensitivity reactions.
Those listed below are commonly used in the industry. As shown, even when diluted with propylene glycol they show very small changes in the comedogenicity.
Butyl stearate and oleyl alcohol are in the extra severe class, promoting comedogenicity on minimally comedogenic substances even when diluted down to concentrations of 5%.
Cosmetics containing these materials should be avoided by people with oily or acne prone skins.
Table 15: Esters and Ethers
Triethyl citrate, water soluble
PPG 2 myristyl propionate
Myristyl myristate
Myristyl propionate
Myreth 3 myristate, 50% in propylene glycol
Myreth 3 myristate, 10% in propylene glycol
PPG 15 stearyl ether
Isocetyl stearate
C12-C15 alcohols benzoate
Butyl stearate, 100%
Butyl stearate, 5% in mineral oil
Isostearyl neopentanoate
Isodecyl isononanate 15-200
Results
0/3
0/3
2/3
2/3
3/3
2-3/3
2/2
0/3
3/3
2/3
1/3
0/3
Quindi Paracelso , se non ho capito male son meno comedogeni i siliconi e i peg ( tanto odiati ) che olii e altre sostanze 'bio'???Te capì...che roba...
Il mio olio di germe grano ( povero non ti fila nessuno mi sa che ti producono solo x me ) non compare nella lista.....Va beh , cmq , grazie delle info....
Ora cari esperti ( Vittorio , Lola , Fabri ecc ) ...via con il dibattito....
( Va che ho pagato il biglietto , quindi esigo uno spettacolo con i fiocchi !!eheheheheheh ..... :P )
Ciao
Il mio olio di germe grano ( povero non ti fila nessuno mi sa che ti producono solo x me ) non compare nella lista.....Va beh , cmq , grazie delle info....
Ora cari esperti ( Vittorio , Lola , Fabri ecc ) ...via con il dibattito....
( Va che ho pagato il biglietto , quindi esigo uno spettacolo con i fiocchi !!eheheheheheh ..... :P )
Ciao
Io ho trovato questo, di Giuseppe Parodi
http://www.giuseppeparodi.it/acne%20%20cosmetica.htm
<<<E' ormai accettato comunemente il concetto che la causa fondamentale dell'acne sia ormonale e su tale concetto ruota gran parte delle analisi e delle terapie dermatologiche .Tuttavia un ruolo eziologico è svolto indubitabilmente anche da fattori esogeni e fra questi ,principalmente,dai cosmetici.
Fu Kligman a introdurre nel 1972 la nozione di "acne cosmetica" Più recentemente,nel suo libro "Acne e rosacea" ha specificato ulteriormente la acne cosmetica differenziando la comedogenicita di un cosmetico dalla acnegenicità dello stesso. Nel primo caso si assiste alla chiusura del follicolo sebaceo, cui segue la comparsa di papulo pustole; nel secondo caso si tratta essenzialmente di un follicolite provocata da sostanze irritanti le quali,danneggiando il follicolo, consentono al sebo di determinare nella cute una reazione tossica. La prima richiede settimane per svilupparsi,la seconda può insorgere rapidamente. Kligman arriva a sostenere per la dermatite periorale, in determinati casi,una origine di questo tipo.
Secondo Kligman molte sostanze utilizzate per la cura dell'acne stessa sono comedogeniche: lo stesso benzoil perossido, o le sostanze che veicolano gli antibiotici topici. Esistono poi sostanze contenute nei detergenti, nei tonici quali conservanti, profumi che pur non essendo comedogeniche possono scatenare l'azione di altre sostanze comedogeniche.
Secondo la Draelos, che ha pubblicato una lista con le sostanze più frequentemente incriminate, un cosmetico che non contenesse neanche una di queste sostanze, difficilmente sarebbe un buon cosmetico. Il problema della comedogenicità - sostiene la Draelos -è molto più complesso di una semplice lista: prodotti che non contengono sostanze presenti nella lista non sono necessariamente non comedogenici;viceversa prodotti che contengono tali sostanze non sono sicuramente comedogeniche: tutto va valutato alla luce della singola reazione di ciascun paziente nei confronti di un prodotto finito,non di una singola sostanza chimica. Ad una simile conclusione era giunto anche un simposio sulla comedogenicità svoltosi all'American Academy del 1988.
La acneicigità di un cosmetico è una evenienza molto più frequente della comedogenicità e per la sua grande variabilità non può essere inquadrata con una semplice lista. Frequente è la comparsa di manifestazioni papulose sulle guance in rapporto alla applicazione di un fondo tinta o di un fard.
La sospensione del cosmetico incriminato normalmente provoca la risoluzione delle lesioni.Nella diagnosi bisogna sempre tener presente che -come dice Kligman- un acne intensamente infiammata molto difficilmente può essere dovuta dai cosmetici.
E'stato inoltre dimostrato che l'uso di detergenti neutri o alcalini per lungo tempo può incrementare lo sviluppo del Propionibacterium acnes.>>>
In pratica... non ci si capisce niente: non sarà mica che l'unica è provare e vedere se un cosmetico crea problemi oppure no? Non ci posso credere :-(
Ma mettiamo il caso delle trentenni moderne, che da almeno dieci anni se non più si spalmano di crema viso, i brufoli se ne vanno a velocità di lumaca e i punti neri, invece, rimangono lì e si riformano nonostante tutti gli strizzamenti, le pulizie del viso, i cosmetici mirati... e per di più per almeno una settimana su quattro lottano coi brufoletti premestruali, come fanno a capire se quel particolare cosmetico è comedogenico?
Cerco la Draelos.
Lola
http://www.giuseppeparodi.it/acne%20%20cosmetica.htm
<<<E' ormai accettato comunemente il concetto che la causa fondamentale dell'acne sia ormonale e su tale concetto ruota gran parte delle analisi e delle terapie dermatologiche .Tuttavia un ruolo eziologico è svolto indubitabilmente anche da fattori esogeni e fra questi ,principalmente,dai cosmetici.
Fu Kligman a introdurre nel 1972 la nozione di "acne cosmetica" Più recentemente,nel suo libro "Acne e rosacea" ha specificato ulteriormente la acne cosmetica differenziando la comedogenicita di un cosmetico dalla acnegenicità dello stesso. Nel primo caso si assiste alla chiusura del follicolo sebaceo, cui segue la comparsa di papulo pustole; nel secondo caso si tratta essenzialmente di un follicolite provocata da sostanze irritanti le quali,danneggiando il follicolo, consentono al sebo di determinare nella cute una reazione tossica. La prima richiede settimane per svilupparsi,la seconda può insorgere rapidamente. Kligman arriva a sostenere per la dermatite periorale, in determinati casi,una origine di questo tipo.
Secondo Kligman molte sostanze utilizzate per la cura dell'acne stessa sono comedogeniche: lo stesso benzoil perossido, o le sostanze che veicolano gli antibiotici topici. Esistono poi sostanze contenute nei detergenti, nei tonici quali conservanti, profumi che pur non essendo comedogeniche possono scatenare l'azione di altre sostanze comedogeniche.
Secondo la Draelos, che ha pubblicato una lista con le sostanze più frequentemente incriminate, un cosmetico che non contenesse neanche una di queste sostanze, difficilmente sarebbe un buon cosmetico. Il problema della comedogenicità - sostiene la Draelos -è molto più complesso di una semplice lista: prodotti che non contengono sostanze presenti nella lista non sono necessariamente non comedogenici;viceversa prodotti che contengono tali sostanze non sono sicuramente comedogeniche: tutto va valutato alla luce della singola reazione di ciascun paziente nei confronti di un prodotto finito,non di una singola sostanza chimica. Ad una simile conclusione era giunto anche un simposio sulla comedogenicità svoltosi all'American Academy del 1988.
La acneicigità di un cosmetico è una evenienza molto più frequente della comedogenicità e per la sua grande variabilità non può essere inquadrata con una semplice lista. Frequente è la comparsa di manifestazioni papulose sulle guance in rapporto alla applicazione di un fondo tinta o di un fard.
La sospensione del cosmetico incriminato normalmente provoca la risoluzione delle lesioni.Nella diagnosi bisogna sempre tener presente che -come dice Kligman- un acne intensamente infiammata molto difficilmente può essere dovuta dai cosmetici.
E'stato inoltre dimostrato che l'uso di detergenti neutri o alcalini per lungo tempo può incrementare lo sviluppo del Propionibacterium acnes.>>>
In pratica... non ci si capisce niente: non sarà mica che l'unica è provare e vedere se un cosmetico crea problemi oppure no? Non ci posso credere :-(
Ma mettiamo il caso delle trentenni moderne, che da almeno dieci anni se non più si spalmano di crema viso, i brufoli se ne vanno a velocità di lumaca e i punti neri, invece, rimangono lì e si riformano nonostante tutti gli strizzamenti, le pulizie del viso, i cosmetici mirati... e per di più per almeno una settimana su quattro lottano coi brufoletti premestruali, come fanno a capire se quel particolare cosmetico è comedogenico?
Cerco la Draelos.
Lola
Mah, Lola, la Zoe Draelos è brava - ma è praticamente una pedina della P&G (leggi...Olay....)
Ci sono tante cose da dire, ma una in particolare:
Paracelso, ma che ti sei fulminato a mandare post così lunghi?????
Va bè che tu hai il pupo insonne....
Non ho mai creduto al test sull'orecchio di coniglio - è una delle prove evidenti della assoluta inutilità dei test di cosmetici su animale.
Il problema della comedogenicità è che la reattività è strettamente legata alla risposta individuale.
Il problema è anche questo: leggendo anche questo forum, mi accorgo che le ragazze si mettono troppe creme e troppi unti sulla pelle, in generale.
E si puliscono male la faccia.
Non serve tutta quella roba che usate - per fare un paragone, sarebbe come stupirsi se ingrassate mangiando 6000 calorie al giorno. Anche se è tutta roba sana e che fa bene.
Discorso assai lungo....
Ciao
Ci sono tante cose da dire, ma una in particolare:
Paracelso, ma che ti sei fulminato a mandare post così lunghi?????
Va bè che tu hai il pupo insonne....
Non ho mai creduto al test sull'orecchio di coniglio - è una delle prove evidenti della assoluta inutilità dei test di cosmetici su animale.
Il problema della comedogenicità è che la reattività è strettamente legata alla risposta individuale.
Il problema è anche questo: leggendo anche questo forum, mi accorgo che le ragazze si mettono troppe creme e troppi unti sulla pelle, in generale.
E si puliscono male la faccia.
Non serve tutta quella roba che usate - per fare un paragone, sarebbe come stupirsi se ingrassate mangiando 6000 calorie al giorno. Anche se è tutta roba sana e che fa bene.
Discorso assai lungo....
Ciao