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Mineral Oil and Petrolatum Safety and Efficacy
By Harold Faust
Most of us take for granted that the products we apply to our skin every day are safe and effective. And for the vast
majority of cosmetics and topical drugs, that is the case. Few products have been used on the skin as long as mineral oil and
petrolatum. Familiar products, such as Blistex®, ChapStick®, Neosporin®, and Vaseline® contain these ubiquitous
ingredients. Many of these topically applied OTC drugs and cosmetics have stood the test of time. Still, mineral oil and
petrolatum are regarded by some cosmetic marketers as not “natural”, out-of-vogue or even unsafe. We could argue that these
products, derived from mother earth, are indeed natural; they are certainly not synthetic. In the past decades, extensive
research has been conducted to measure the safety and effectiveness of hydrocarbons. This paper concentrates on the safety
and efficacy of the ubiquitous hydrocarbons; Mineral Oil and Petrolatum.
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Mineral Oil and Petrolatum Regulation
Mineral oils are composed primarily of saturated
hydrocarbons. Most of those hydrocarbons are saturated rings
(cyclo-paraffins) or branched chain paraffins (iso-paraffins).
Petrolatum contains many of the same structures but petrolatum
also contains some n-paraffins and a substantial concentration of
higher molecular weight paraffins (microcrystalline wax). In other
words, petrolatum contains components referred to as mineral oils
and microcrystalline waxes. In some of the studies cited in this
paper, petrolatum per se was not listed as a test material, but the
components, mineral oils and petroleum waxes were, and
therefore any statements that reference safety and efficacy are still
valid for petrolatum.
For decades, consumers have been using cosmetics that
contain refined petroleum-based ingredients. It is imperative to
recognize that the degree of refinement of mineral oil and
petrolatum is the key to safe and successful cosmetic formulations.
Simply using the terms “mineral oil” or “white oil” or
“petrolatum” or “petroleum jelly” is not sufficient. Even the CAS
(Chemical Abstract Services)I registry numbers for these materials
do not fully distinguish quality or refinement. If the term mineral
oil is not properly defined, it can refer to the oils used in industrial
and automotive lubricants. Likewise, unrefined petrolatum can
also be used in industrial applications. Some published reports
have not clearly distinguished between refined grades of mineral
oils and actually refer to lesser refined mineral oils in the same
context as the fully refined grades that are used in cosmetic and
pharmaceutical applications. This is a misrepresentation that has
resulted in confusion in the industry over time.
Point in case is the CAS number normally used for
petrolatum; 8009-03-8, which does not say anything about the
degree of refinement of that petrolatum. In essence, the same
number is used for raw and refined petrolatum. As a result,
petrolatum with the CAS number 8009-03-8 was included the
EU’s Consolidated List of C/M/R (Carcinogens, Mutagens, or
Toxic to Reproduction) Substances1. However, that petrolatum
entry does include the notation; “N” that states: “The classification
as a carcinogen need not apply if the full refining history is known
and it can be shown that the substance from which it is produced
is not a carcinogen.” Clearly, “the full refining history” of USP
grade petrolatum exempts them from the list; yet, this is rarely and
often ineffectively communicated to cosmetic scientists and
formulators alike. A detailed explanation of petrolatum CAS
issues was described by the author at the November 2003 NPRA
I
(National Petrochemical & Refiners Association) meeting in Houston,
TX, where the author advocated for accurate understanding and
communication on the actual refined state of petrolatum2.
The specifications for mineral oil and petrolatum were established
many years ago by pharmacopeias in the US, Europe, and Japan. The
US FDA also established purity tests that are published in the Code of
Federal Regulations (CFR). Products that pass these tests are allowed
to be used in both direct and indirect food applications. Similar
specifications are found in the Food Chemical Codex3.
For
formulators, it is important that they choose ingredients that are
certified by the manufactures to comply with White Petrolatum USP,
Petrolatum USP (Yellow), Mineral Oil USP (Heavy), or Light Mineral
Oil NF standards 4. For North America, the established manufacturers
also certify that these products meet the purity requirements in 21 CFR
172.880 and 21 CFR 172.878 (for petrolatum and mineral oil,
respectively). Depending on their physical properties, these products
will also comply with similar monographs in the pharmacopeias for
Europe and Japan.
Allergenicity, Carcinogenicity and Comedogenicity
Naturally, the first question that arises about topically applied
products is the degree to which they are absorbed into or passed
through the skin. Elias, Ghadially, et al did extensive research on skin
absorption of hydrocarbons5 6. Those studies showed that typical
hydrocarbons found in petrolatum and mineral oil penetrate into the
outer layer of the epidermis, the stratum corneum (SC), but very little
reaches the lower layers of the epidermis and virtually none of the
hydrocarbons reach the dermis. Therefore, any reports that topically
applied mineral oil or petrolatum are absorbed through the skin and
have a systemic effect, are in conflict with the published literature.
In addition to their long history of use on human skin of all ages,
mineral oil and petrolatum are among the most extensively tested
materials in the world. In years past, animal testing was common.
However, today such testing is discouraged officially in Europe and
unofficially in much of the rest of the world. In the 1980’s, mineral oil
and petrolatum were shown to have no adverse effects in eye and skin
testing on rabbits in studies conducted by an AAALAC accredited
laboratory7. The fact that mineral oil and petrolatum are so inert is
certainly a contributing factor to why they do not typically cause
allergic reactions when applied to the skin. They are primarily
composed of saturated hydrocarbons, which do not easily oxidize or
metabolize. In the absence of proteins, carbohydrates, fatty acids,
fragrance chemicals, pesticide residues, etc. it is understandable why
these materials do not cause harm to the skin.
Doom-Goossens of the Katholieke Universiteit Leuven monitored
the allergic responses to petrolatum containing products in Belgium
over a five-year period8. Only three cases of allergencity were reported
CAS numbers are issued by the American Chemical Society
1
even though the petrolatum was used in over 500 products and it was
concluded that allergic reactions to refined petrolatum are rare.
As research on hydrocarbon allergenicity continued, another
study was commissioned to measure skin sensitization by
petrolatum. This time, Guinea Pig Sensitization tests using
petrolatum were reported by Mahagaokar9. In this study, five male
and five females were tested using the EPA Pesticide Assessment
Guidelines of 1984 with the Beuler modification10 11. A positive
control consisted of 1.0 % DNCB (1-chloro2,4-dinitrobenzene) in
ethanol for the induction dose and 0.15 % DNCB in ethanol for the
challenge dose. After the initial induction with petrolatum, the
animals were given a two-week rest period before the challenge
dose. As shown in Table 1 below, the petrolatum produced no
effects at 24 hours and at 48 hours after challenge. This again
supports the absence of skin sensitization in case of refined
petrolatum.
Table 1: Guinea Pig Sensitizations Tests using Penreco, White
Petrolatum USP. S. Mahagaokar, J. Toxicol. – Cut. & Ocular
Toxicol. 15(4), 315 – 323 (1996)
White Petrolatum USP, Penreco
Naïve Control
DNCB in ethanol
Naïve control challenged, DNCB
At Induction
Erythema/ Edema
Day 1
Day 8
Day 15
0
0
0
0.3
3.0
3.0
After Challenge
Erythema/ Edema
24 Hr
48 Hr
0
0
0
0
1.5
1.7
0
0
Polycyclic Aromatic hydrocarbons (PAHs) are the only nonsaturated hydrocarbons found in mineral oil and petrolatum that are
of concern. The levels of PAH are very low in petrolatum and even
lower in mineral oil and these low levels are dictated by the FDA
purity regulations sited above. The related FDA tests involve a
series of extractions of PAHs, with the dipolar but aprotic solvent,
DMSO (dimethyl sulfoxide). The total UV absorbance, measured
over specified wavelengths, must not exceed the limits published in
the CFR. Such tests do not limit individual PAHs but rather limit the
absorbance and therefore the sum of all aromatic hydrocarbons that
absorb in the wavelengths of the method. Recently a sample of
White Petrolatum USPII was tested for specific PAHs by the
Biochemisches Institut für Umweltcarcinogene in Germany12. Out
of the 28 individual PAHs analyzed using the Grimmer method,
none exceeded 10 micrograms per Kilogram (ppb). This indicates
that even though the Polycyclic Aromatic hydrocarbons are present,
the levels are so low that it is inconsequential.
Since mineral oil and petrolatum have been used in food
applications, it is natural to expect that regulators would request
extensive testing for those particular applications. This was
originally done in the 1950’s and 1960’s before the FDA approved
the use of these materials for food contact. Shubik, Lijinsky, et al at
The Chicago Medical School undertook a large program of research
on 36 samples of petroleum waxes typically found in petrolatum13.
Their work involved lifetime feeding studies of rats with waxes at 10
% of the diet. They also conducted repeated skin painting
experiments on mice and rabbits. The results showed absolutely no
carcinogenic response when compared with control groups. Another
group of researchers at the FDA laboratories and the Sloan Kettering
Institute investigated several commercial sources of petrolatum in rat
and mice diets14. This work also resulted in the same conclusion that
there was “no toxic or carcinogenic response” after 2 years in the rat
diets, essentially deeming petrolatum safe for direct and in-direct
contact.
II
Calumet Penreco Ultima of White Petrolatum USP
More recently, several rat feeding studies were conducted using
various mineral oils and petroleum waxes15 16 17. It was concluded that
a small portion of the hydrocarbons in low and medium viscosity
mineral oils as well as in a low melting point wax, were absorbed in
the 90-day feeding period. They accumulated in the livers and
mesenteric lymph nodes of 344 Fisher rats. This resulted in the
formation of lipogranulomas in the mesenteric lymph nodes and in the
livers. Pathologists described this as a normal inflammatory response
to a foreign substance and it was not considered toxic to the animals18
19
. The higher molecular weight oils and waxes were not absorbed in
the 90-day feeding period and therefore they showed no treatment
related effects. The immune systems of the rats treated the materials as
they would any foreign substance, and attempted to eliminate them.
During several of the studies the mineral oil and wax dosages were
suspended after 90 days. The animals were fed the normal diet for an
additional 28 days in one study and another 85 days in another. There
was a clear reversal of the effects in the liver and mesenteric lymph
nodes. It appeared that the hydrocarbons were so inert it simply took
some time for them to begin to be metabolized. Another protocol
involved a two year feeding study of Fisher rats and the results were
similar. All of the studies indicated a greater absorption for lower
molecular weight hydrocarbons and a decreased absorbance of higher
molecular weight components.
An additional Japanese study using a mixture of eight different
sources of mineral oils was conducted in 199720. It was specifically
undertaken to look for the carcinogenicity potential of the mineral oils
by ingestion of Fisher rats. They found “no statistically significant
increase in the incidence of any tumor type.” After numerous animal
feeding studies by several laboratories involving hundreds of rats, there
was no evidence of a carcinogenic response to ingestion or topical
application of either mineral oil and/or petrolatum.
Similarly, researchers have found that cosmetic grade mineral oil
and petrolatum are non- comedogenic. It is understandable that people
think that the oily nature of these materials could cause acne. However,
Kligman’s 1996 article entitled: “Petrolatum is not Comedogenic in
Rabbits or Humans: A critical reappraisal of the rabbit ear assay and
the concept of “acne cosmetica”, attempted to set the record straight.
In it he pointed out that “comedogenicity has nothing whatever to do
with oiliness” of the products used. 21
Key Moisturization Properties
Healthy and vibrant skin depends on water entrained in the
Stratum Corneum (SC). The natural moisturization factor (NMF) in
the corneocytes (keratinocytes) of the SC bind water inside of these
cells. The surrounding lipid bilayers that make up the mortar of the so
called “brick and mortar” model of the SC helps retain water. For
normal skin under ideal conditions, it may not be necessary for people
to use moisturizers. Unfortunately, skin is not always normal and
conditions are not always ideal. The atmosphere is often low in
humidity, especially in the winter months in northern climates.
Frequent washing of the skin tends to remove some the lipids as well
as corneocytes. Moreover, various skin diseases and the aging process
lead to dryer skin or Xerosis.
It is well known that mineral oil and petrolatum are effective
moisturizing agents because they are occlusive to the skin. This means
that they form a waterproof barrier that reduces the loss of moisture
that is naturally part of the SC. In fact, petrolatum is regularly used as
positive control for moisturization testing.
Dr. Leslie Bauman, MD, states in her 2009 text book, Cosmetic
Dermatology, “Two of the best occlusive ingredients currently
available are petrolatum and mineral oil” 22. Chapter 12 of Leyden
and Rawlings’s 2002 book entitled Skin Moisturization points out that
“petrolatum is considered a standard emollient for comparative
testing of hydration and barrier repair”23.
Kligman used clinical regression methods to evaluate the
effectiveness of various moisturizers24. Instrumental methods are
widely used today to quantitatively measure TEWL (TransEpidermal Water Loss). Table 2 shows typical results of such tests
that were run on human volunteers using one of the most popular
grades of petrolatum, Snow White Petrolatum USPIII. The results
show a consistent decrease in the loss of moisture from the skin.
It should be pointed out that petrolatum has no volatile
hydrocarbons or water that can sometimes interfere with this test.
worked with other organizations such as the Personal Care Products
Council on projects involving mineral oil and petrolatum. Mr. Faust
currently works for Calumet Specialty Product Partners, in the Karns
City, PA facility. For more information or to contact the author, please
visit www.calumetspecialty.com.
References
1
2
Table 2: TEWL (g/m /hr) Results on Human Volunteers using
Various Batches of Snow, White Petrolatum USP (Thomas J.
Stephens & Associates)
Year
Meth
1996
1999
2005
A
B
C
Methods:
TEWL Hours after applications to volar forearms or legs
Base1-Hour
2-Hour
3-Hours
24-Hours
line
(Decrease)
( Decrease)
( Decrease)
( Decrease)
8.97
6.64
7.65
4.63 (48%)
4.64 (30 %)
2.80 (64 %)
4.83 (46%)
4.28 (35 %)
2.84 (63 %)
4.93 (45%)
4.13 (38%)
2.73 (66 %)
7.18 (20%)
5.90 (11%)
7.29 (5 %)
A: ServoMed® Evaporimeter, Forearms
B: ServoMed® Evaporimeter, Legs
C: Dermalab® Evaporimeter, Forearms
The Ghadially, Sorenesen and Elias’s paper sited earlier made
use of Evaporimetry to measure enhanced barrier recovery of
human skin using petrolatum treatment. The lipids in the SC
were partially removed using acetone. This increased the TEWL
levels to at least 16g/m2/Hr. The petrolatum treated areas
consistently showed faster barrier recovery than the untreated
areas. Additionally, they demonstrated that petrolatum did not
interfere with the natural replacement of lipids in the SC of mice.
The implication is that petrolatum may function beyond simply as
an occlusive agent on the skin and actually provides barrier
recovery.
Conclusion
Throughout this report, we have pointed out that extensive
research revealed no evidence that that mineral oil and petrolatum,
that have been refined to meet the most stringent purity
specifications, are harmful to the skin in any way. On the
contrary, they provide moisturization and barrier repair to
damaged skin. Unlike some natural products that can have
variable compositions and have not been extensively tested,
mineral oil and petrolatum have consistent compositions and have
been used on human skin as long as any modern cosmetic
ingredient. In fact, they are still used in many of the most popular
brands to date. Their safety has been confirmed by its long-term
use and by multiple studies indicating that both mineral oil and
petrolatum are not comedogens, irritants, allergens and certainly
not carcinogens.
Author Biography
Harold Faust holds a BS in Chemistry from Duquesne
University and has worked with raw materials for the Personal
Care/Pharmaceutical industry for more than 38 years. He has held
laboratory and technical service positions for global organizations
such as Penreco, ConocoPhillips, Pennzoil and Calumet and has
published several articles in technical journals on Mineral Oil and
Petrolatum. Mr Faust is a member of the SCC, ACS and has
III
Snow, White Petrolatum USP is a product name owned by Calumet Penreco
LLC.
European Union, Directive 76/769/EEC.
Faust, H. R., Casserly, E. W., Petrolatum and Regulatory Requirements,
NPRA Publication LW-03-132, www.npra.org, (2003).
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States Pharmacopeia Convention, Rockville, MD.
4 U.S. Pharmacopeia 35/ National Formulary 30, United States Pharmacopeial
Convention, Inc., Rockville, MD, 2012.
5 Ghadially, R, Halkier-Sorensen , P.M. Elias, Effects of Petrolatum on
Stratum Corneum Structure and Function. J. Am. Acad. Dermatol. ; 26: 387396, (1992).
6 Brown, B.E., Diembeck, W, Hoppe, U., Elias, P. M., Fate of Topical
Hydrocarbons in the Skin. J. Soc. Cosmet. Chem., 46: 1-9, (1995).
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4592-86, 4595-86, 4596-86, 4600-86. Sponsored by Pennzoil Products Co.
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Universiteit Leuven (1982).
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Toxicology and Applied Pharmacology 7, 382-401 (1965).
15 Baldwin, M.K. et al, Feeding Studies in Rats with Mineral Hydrocarbons
Food Grade White Oils, Toxicologic Pathology, 20, 3, 426 – 435 (1992).
16 Smith, J.H. et al. Ninety-Day Feeding Study in Fisher 344 Rats of Highly
Refined Petroleum Derived Food Grade White Oils and Waxes, Toxicologic
Pathology 24, 2, 214-230, (1996).
17 Priston, R.A., Riley, A.J., Chronic Toxicity Studies on White Oils,
CONCAWE Report No. 1/04, www.concawe.org, (2004).
18 Fleming, K.A. et al Granulomas in the livers of humans and Fisher rats
associated with the ingestion of mineral hydrocarbons: a comparison.
Regulatory Toxicology and Pharmacology, 27, 75-81, (1998).
19 Zimmerman, H. J. et al Significance of Studies / Review of Pathology. The
Toxicology Forum Special Meeting on Mineral Hydrocarbons, September 21 –
23, Green College, Oxford, UK, 102 – 108 (1992).
20 Shoda, T. et al, Lack of Carcinogenicity of Medium Viscosity Liquid
Paraffin Given in the Diet of F344 Rats, Food and Chemical Toxicology, 35,
1181 – 1119 (1997).
21 Kligman, A. M. Petrolatum is Not Comedogenic in Rabbits or Humans: A
critical Reappraisal of the Rabbit Ear Assay and the Concept of “Acne
Cosmetica”, J. Soc. Cosmet. Chem. 47, 41 – 48 (1996).
22 Baumann, L. et al, Cosmetic Dermatology Principles and Practices, McGraw
Hill Medical, (2009).
23 Leyden, J. J., Rawlings, A. V., Skin Moisturization, Marcel Dekker, Inc.
(2002).
24 Kligman A. Regression method for assessing the efficacy of moisturizers.
Cosm Toiletr., 93; 27 (1978).
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