Quick Search

PRODUCTS

ETHYL HEXYL DIMETHYL PABA

CAS Number:    21245-02-3

Synonyms:

arlatone UVB
benzoic acid, 4-(dimethylamino)-, 2-ethylhexyl ester
benzoic acid, p-(dimethylamino)-, 2-ethylhexyl esterescalol 507
2-ethyl hexyl 4-(dimethyl amino) benzoate
2-ethylhexyl 4-(dimethylamino)benzoate
2-ethylhexyl p-(dimethylamino)benzoate
2-ethylhexyl p-dimethylaminobenzoate
 eusolex 6007
 octyl dimethyl p-aminobenzoate
 octyl dimethyl paba
 padimate O
escalol 507
PI EHA;Sundown;YF-PI EHA;Escalol507;Padimate 0;IHT-PI EHA;PADIMATE O;HRcure-EHA;Pademat -O;SYNCURE EHA
2-ETHYLHEXYL P-(DIMETHYLAMINO)BENZOATE
4-DIMETHYLAMINOBENZOIC ACID 2-ETHYLHEXYL ESTER
ETHYLHEXYL(2-)-4-DIMETHYLAMINOBENZOATE
EUSOLEX(R) 6007
N,N-DIMETHYL-4-AMINOBENZOIC ACID 2-ETHYL-HEXYL ESTER
N,N-DIMETHYLAMINOBENZOIC ACID ISOOCTYL ESTER
OCTYL 4-DIMETHYLAMINOBENZOATE
OCTYL-4-N,N-DIMETHYLAMINOBENZOATE
octyl dimethylaminobenzoate
OCTYL DIMETHYL PABA
OCTYL DIMETHYL-P-AMINO-BENZOATE
OCTYL P-DIMETHYLAMINOBENZOATE
PADIMATE O
P-DIMETHYL-AMINOBENZOIC ACID ISOOCTYL ESTER
SYNCURE EHA
TIMTEC-BB SBB008471
4-(dimethylamino)-benzoicaci2-ethylhexylester
Arlatone UVB
Benzoic acid, 4-(dimethylamino)-, 2-ethylhexyl ester
Benzoicacid,4-(dimethylamino)-,2-ethylhexylester
Ethylhexyl Dimethyl PABA (Padimate O)
2-Ethylhexyl 4-(dimethylamino)benzoatato
Sundown
Benzoic acid, 4-(dimethylamino)-, 2-ethylhexyl ester
2-Ethylhexyl 4-(dimethylamino)benzoate
Escalol 507
Octyl-dimethyl-PABA (OD-PABA)(Padimate O)
Padimate-O
4-(Dimethylamino)benzoic Acid 2-Ethylhexyl Ester
Radiacare Lip Balm
2-Ethylhexyl p-Dimethylaminobenzoate
N,N-dimethyl-p-aminobenzoic acid-2-ethylhexyl ester
Arlatone UVB
Padimate O
2-ethylhexyl N,N-dimethyl-p-aminobenzoate
2-ETHYLHEXYL-P-DIMETHYL-AMINOBENZOATE
Oxifenamate
MFCD00017526
Quantacure EHA
Octyl p-Dimethylaminobenzoate
2-Ethylhexyl 4-dimethylaminobenzoate
2-Ethylhexyl-4-dimethylaminobenzoate
EINECS 244-289-3
p-dimethylaminobenzoic acid 2-ethylhexyl ester
2-ethylhexyl 4-N,N-dimethylaminobenzoate
Octyl 4-(Dimethylamino)benzoate
p-(Dimethylamino)benzoic Acid 2-Ethylhexyl Ester; 2-Ethylhexyl 4-(N,N-Dimethylamino)benzoate; 2-Ethylhexyl 4-(dimethylamino)
benzoate; 2-Ethylhexyl N,N-dimethyl-p-aminobenzoate; 2-Ethylhexyl p-(N,N-dimethylamino)benzoate; 2-Ethylhexyl p-
(dimethylamino)benzoate; 4-(Dimethylamino)benzoic Acid 2-Ethylhexyl Ester; Arlatone UVB; Chivacure OPD; EHDAB; Esacure
EHA; Escalol 507; Eusolex 6007; Genocure EHA; ODPABA; Octyl dimethyl PABA; Omnirad EHA; Padimate O; Quantacure EHA;
Speedcure EHA


Ethylhexyl Dimethyl PABA is a yellowish, oily liquid. In cosmetics and personal care products, Ethylhexyl Dimethyl PABA is used in the formulation of sunscreen products, shampoos, conditioners, hair sprays, makeup, and bath and skin products.
 

Ethylhexyl Dimethyl PABA is a yellowish, oily liquid. In cosmetics and personal care products, Ethylhexyl Dimethyl PABA is used in the formulation of sunscreen products, shampoos, conditioners, hair sprays, makeup, and bath and skin products.

When it is used in sunscreen drug products, Ethylhexyl Dimethyl PABA is called Padimate O.

This chemical is used as a UVB absorbing agent in sunscreens, cosmetic creams,
lotions, lipsticks, sun oils, moisturizers and nail polishes. Further research may identify
additional product or industrial usages of this chemical. 

Ethylhexyl Dimethyl PABA. Escalol™ 507 UV filter acts as a UV filter. It is a powerful oil-soluble UV-B absorber and offers protection against UV-B and UV-A radiation. It provides cost-effective performance and excellent safety profile. Escalol™ 507 UV filter finds application in formulating sun-care (after-sun, self-tanning and sunscreen application), body- & facial-care formulas and color cosmetics.

Ethylhexyl Dimethyl PABA is a yellowish, oily liquid. Ethylhexyl Dimethyl PABA is used in the formulation of sunscreen products, shampoos, conditioners, hair sprays, makeup, bath and skin products in cosmetics and personal care products.

Padimate O. to Ethylhexyl Dimethyl PABA when used in sunscreen drug products.

This chemical is used as a UVB absorbing agent in sunscreens and cosmetic creams.
lotions, lipsticks, sunscreen oils, moisturizers and nail polishes. More research can identify
additional product or industrial uses of this chemical.

Ethylhexyl Dimethyl PABA. Escalol ™ 507 UV filter acts as a UV filter. It is a powerful oil-soluble UV-B absorber and provides protection against UV-B and UV-A radiation. It provides cost effective performance and excellent safety profile. Escalol ™ 507 UV filter finds application in the formulation of sun care (after sun tanning, self-tanning and sunscreen application), body and face care formulas, and color cosmetics.

Ethylhexyl dimethyl para-aminobenzoic acid (PABA) is an oily yellow liquid derivative of water-soluble PABA
commonly used in sunscreen. Ethylhexyl dimethyl PABA is widely used as an ingredient in many cosmetics at an
average concentration of 1.25% (0.5-2.0%) in Korea. Previous studies, including those involving animals, have
demonstrated that ethylhexyl dimethyl PABA is toxic to the following four organs: testis, epididymis, spleen, and
liver. In addition, experiments using human keratinocytes found that ethylhexyl dimethyl PABA inhibits cell
growth and DNA synthesis at low concentrations, and halted the cell cycle of MM96L cells (human melanoma
cell line) at the G1 phase. Despite limited clinical data in humans, many studies have confirmed increased mutagenicity
of ethylhexyl dimethyl PABA following exposure to sunlight, which suggests that this molecule is likely
to contribute to onset of sun-induced cancer despite protecting the skin through absorption of UVB. For risk
assessment, the no observed adverse effect level (NOAEL) chosen was 100 mg/kg bw/day in a 4 weeks oral toxicity
study. Systemic exposure dosage (SED) was 0.588 mg/kg bw/day for maximum use of ethylhexyl dimethyl
PABA in cosmetics. Based on the risk assessment and exposure scenarios conducted in this study, the margin of
safety (MOS) was calculated to be 180.18 for a sunscreen containing 8% ethylhexyl dimethyl PABA, which is the
maximum level allowed by the relevant domestic authorities.

Ethylhexyl dimethyl PABA (CAS No. 21245-02-3) is an
organic derivative of water-soluble PABA (4-aminobenzoic
acid) included in sunscreen and other cosmetics. It is
a yellow water-insoluble oily liquid with an ester bond
formed by condensation of 2-ethylhexanol and dimethylaminobenzoic
acid (Fig. 1). Ethylhexyl dimethyl PABA is also known as padimate O, OD-PABA, or octyl dimethyl
p-aminobenzoate (Table 1). The Ministry of Food and
Drug Safety (MFDS) and US Food and Drug Administration
(FDA) mandate that its concentration in any cosmetic
product shall not exceed 8% (1). Previous animal studies
showed that high concentrations of ethylhexyl dimethyl
PABA may be toxic to the epididymis and caution should
be exercised when administering this substance to infants

PHYSICAL AND CHEMICAL PROPERTIES
The range of purities of ethylhexyl dimethyl PABA used
as a raw material for cosmetics is approximately 98-
99.5%. It is an oily yellow liquid state with oil characteristics.
It has a molecular weight of 277.4053. It is soluble in
alcohol, and strong acid and base, but is insoluble in water
and acetic acid

COSMETIC USE
Ethylhexyl dimethyl PABA is used in sunscreen and in a
variety of beauty products. According to the Environmental
Working Group (EWG) database, it is used in many
products including lipstick, conditioner, shampoo, antiaging
agents, hair spray, and sunscreen. Use of ethylhexyldimethyl PABA in non-cosmetic products has not been
reported in Korea. According to a survey conducted by the
MFDS the average concentration of ethylhexyl dimethyl
PABA in cosmetic products is 1.25% (ranging from 0.5-
2.0%).

HAZARD IDENTIFICATION
Single and repeated dose toxicity studies of ethylhexyl
dimethyl PABA have identified various toxicities including
skin irritation, reproductive toxicity, genotoxicity, and
phototoxicity. Repeated dosing of experimental animals
resulted in organ toxicity and organ pigmentation. The
major proposed mechanism of ethylhexyl dimethyl PABA
toxicity is DNA damage by light-modified ethylhexyl
dimethyl PABA.

General toxicity. In an acute toxicity study of ethylhexyl
dimethyl PABA, the LD50 in rats was 14,900 mg/kg
(3) and no irritation was observed in a human patch test
using white Vaseline® mixed with 8% ethylhexyl dimethyl
PABA.
According to a report by the Scientific Committee on
Cosmetology (SCC) (1999) (4), a 4-week oral administration
study was conducted in rats in accordance with GLP
principles. Ethylhexyl dimethyl PABA was administered
orally (by gavage) at doses of 0, 100, 300, and 1,000 mg/
kg/day (Groups 1, 2, 3, and 4, respectively) to 10 male and
female rats per group. An additional 5 male and 5 female
rats were added to Groups 1 and 4 to evaluate the convalescence
stage. No clinical symptoms were observed except
salivation in Group 4 and decreased weight in Group 4
three to four weeks after administration, which did not
normalize following the convalescence period. Gross
inspections during autopsies of the animals found that the
capsule of the spleen was severely degraded in one female
in Group 4. A male in Group 4 (4/10) exhibited a softened
testis and 8 males exhibited reduced testis size. No prostate, epididymis, or seminal vesicle abnormalities were
observed. Three out of the five males in the Group 4 convalescence
group exhibited reduced testis size. A female
rat in Group 4 showed increased spleen weight, and the
females in Groups 3 and 4 exhibited increased liver weight.
Furthermore, the males in Group 4 exhibited liver weight
gain and pituitary gland weight loss. Among the animals
in the convalescence group, the males in Group 4 exhibited
kidney weight gain, but showed no changes in testis
or pituitary gland weights. Histopathological examinations
showed moderate or moderately severe testicular atrophy
in all males in Group 4 and epididymal edema in seven
out of the ten males in Group 4. All males in Group 4 had
spleen pigmentation, but spleen pigmentation was more
conspicuous in the females in Group 3 and was extensive
in the females in Group 4. The NOAEL was determined at
100 mg/kg/day based on pigmentation of the spleen (5).
The SCC determined that this NOAEL may have been too
conservative, so a NOAEL value of 300 mg/kg/day was
assigned to ethylhexyl dimethyl PABA (4).
No toxicity was observed in 20 rabbits administered 140
or 280 mg/kg/day of ethylhexyl dimethyl PABA for 13
weeks (4).
Mutagenicity/Genotoxicity. In vivo micronucleus testing
was conducted on mice to evaluate mutagenesis. Ethylhexyl
dimethyl PABA (5,000 mg/kg) was intraperitoneally
injected into three groups of mice (n = 10 mice per group;
30, 48, or 72 hr), resulting in no mutagenesis (3).
A chromosomal aberration test was performed in human
lymphocytes. This assay is based on metabolic activation
in response to the S9 mix. Ethylhexyl dimethyl PABA was
dissolved in ethanol at concentrations of 315 to 5,010 μg/
mL. No chromosomal aberrations were observed (4).

Carcinogenicity. Ethylhexyl dimethyl PABA is not
considered carcinogenic per International Agency for
Research on Cancer (IARC), Association Advancing Occupational
and Environmental Health (ACGIH), US National
Toxicology Program (NTP), and Occupational Safety and
Health Administration (OSHA)

Ocular irritation. Two percent ethylhexyl dimethyl
PABA mixed with mineral oil was applied to the eyes of
rabbits. No irritation was reported when both eyes are
washed and left unattended (3).
A slight irritation was observed in rabbit mucous membranes
during a Draize test with 2% and 5% ethylhexyl
dimethyl PABA in mineral oil
Skin irritation. Five percent ethylhexyl dimethyl PABA
mixed with mineral oil applied to rabbit skin did not cause
irritation (3,8). In addition, a patch containing ethylhexyl
dimethyl PABA dissolved in 4% white Vaseline® affixed
to adult volunteers did not cause skin sensitization (3).
No irritation was observed following application of 5%
ethylhexyl dimethyl PABA to normal and damaged rabbit
skin for 24 hr (4).
A human patch test study showed no incidence of irritation
following application of yellow soft paraffin with 5%
ethylhexyl dimethyl PABA for 48 hr (4).
When 1 mg/mL of estradiol was prescribed during the
autumn and winter seasons to postmenopausal women (4
persons), women receiving hormone replacement therapy,
women with sensitivity to ethylhexyl dimethyl PABA,
women with epilepsy, or women prescribed medications to
control liver metabolism (aged between 54 and 63, body
weight between 67 and 93 kg) along with ethylhexyl
dimethyl PABA applied to their arm over a 10 cm2 area,
daily for nine days, no skin irritation was observed (9).

Skin sensitization. Five percent ethylhexyl dimethyl
PABA in mineral oil did not cause skin sensitization in
guinea pigs. In addition, 50 μL of 0.1% ethylhexyl dimethyl
PABA in saline was injected into ten guinea pigs, followed
by nine additional 0.1 mL injections administered
across three weeks. The guinea pigs did not exhibit sensitization
when challenged with a 0.05 mL dose after a 12-
week resting phase (4).
No skin sensitization was observed in humans following
application of 1.5% or 4% ethylhexyl dimethyl PABA
mixed with white Vaseline® (3). Furthermore, 15 volunteers
were instructed to apply soft paraffin containing 4%
ethylhexyl dimethyl PABA for three weeks, followed by a
challenge application after a two week rest phase, after
which no skin sensitization was observed. Consistent with
this result, 150 individuals subjected to a patch test with
7% ethylhexyl dimethyl PABA with 3% oxybenzone did
not exhibit skin sensitization (4). Another study showed
that application of soft paraffin containing 7% ethylhexyl
dimethyl PABA to 156 individuals did not cause sensitization
(4). Finally, a slight stinging reaction was reported
during the induction period when a mixture of 3% benzophenone
and 8% ethylhexyl dimethyl PABA was applied
to 90 individuals, but no skin sensitization was observed

Phototoxicity/Photosensitization. Ten guinea pigs
had their ear hair removed and a mixture of 3% oxybenzone
and 7% ethylhexyl dimethyl PABA was applied to
one ear several times, and 8-methoxypsoralen was applied
to the ears of two guinea pigs as a positive control. The
guinea pigs were then exposed to UV radiation for two
hours. No phototoxicity was observed. Furthermore, no
phototoxicity was observed when ethylhexyl dimethyl
PABA was applied to the posterior of guinea pigs for 2 hr
followed by irradiation of 3 J/cm2 at 320-400 nm (4).
No phototoxicity was observed in 26 individuals who
were tested with 3% oxybenzone and 7% ethylhexyl
dimethyl PABA (4). Furthermore, no phototoxicity was
observed when 5% ethylhexyl dimethyl PABA in ethanol
was applied and the site was irradiated with 30 J (4).
Patch testing with a mixture of 2% oxybenzone and 7%
ethylhexyl dimethyl PABA for 24 hr was conducted on ten
white-skin individuals. Following removal of the patch,
the site was irradiated with UVA for 12 min followed by 1
MED (minimal erythema dose) of UVB. No phototoxicity
was observed in this study (4). Furthermore, human
subjects treated every 26 hr with an emulsion of stearic
acid (3%), water (91%), and 4% ethylhexyl dimethyl
PABA showed no phototoxicity. 
Ethylhexyl dimethyl PABA is harmless unless it is
exposed to light. However, once activated by light, it
directly damages DNA. Ethylhexyl dimethyl PABA in
commercially available sunscreen products can be activated
by UVA, and to a greater extent by UVB, when
exposed to sunlight (10).

Toxicokinetics. To determine whether a new metereddose
topical aerosol (MDTA) medication containing ethylhexyl
dimethyl PABA as a skin penetration enhancer
could enhance transdermal delivery of estradiol, estradiol
MDTA containing ethylhexyl dimethyl PABA was applied
to the abdomens of postmenopausal women for nine days
and the levels of estradiol and estrone in the blood were
measured daily via radioimmunoassay. Following MDTA
treatment, 1 mg of estradiol sprayed onto three adjacent
areas of skin (10 cm2) on the abdomens of each subject did
not induce skin irritation. Blood estradiol concentrations
were measured in four women (aged between 54 and 63
years, body weight between 67 and 93 kg). The average
blood estradiol concentration was 53 pg/mL across the 9-
day study period, which was significantly greater than the
reference value of 13 pg/mL. (p < 0.001). This test confirmed
that the MDTA containing ethylhexyl dimethyl
PABA enhanced transdermal delivery of estradiol (9).
14C-labelled ethylhexyl dimethyl PABA in ethanol was
applied to 100 cm2 of the forearms of each of four male
and female subjects. The forearms were then covered with
gauze for 24 hr after the ethanol completely evaporated.
Blood was collected after 0, 2, 4, 8, 24, and 72 hr and
urine was collected for 24 hr. No radioactivity was found
in the blood samples while 2.45% and 1.18% radioactivity
were found in the urine samples of the male and female
subjects, respectively (average % of total radioactivity).
The average radioactivity recovered after washing the skin
at the application site was 95.7%. Assuming that 0.5 mg/
cm2 was applied at a concentration of 8% to 1.8 m2, the
total amount absorbed was 13 mg, or 0.2 mg/kg (4).
An oil-in-water emulsion lotion was used for an in vitro
percutaneous penetration test, and guinea pig and human
skin were used as the membranes. HEPES-buffered Hank’s
balanced salt solution containing gentamycin sulfate and
bovine serum albumin was used as the aqueous solution in
the receiving chamber. The total absorption rate of ethylhexyl
dimethyl PABA transferred to the receiving chamber
and the skin was 12.7 ± 2.5%. Evaluation of ethylhexyl
dimethyl PABA metabolism was also included in this test.
Guinea pig skin hydrolyzed approximately 13-35% of ethylhexyl
dimethyl PABA transferred to the aqueous solution
through esterase activity, while human skin hydrolyzed
37% of ethylhexyl dimethyl PABA (11).
The value used for skin absorption in humans for the
risk assessment was 2.45% based on the limited skin absorption
data.
Miscellaneous materials (including clinical data).
Cell tests confirmed that ethylhexyl dimethyl PABA inhibited
cell growth and DNA synthesis, and delayed cycle
progression at 25-100 mg/mL. The CI80-13S cell line, a
model of mitochondrial dysfunction, showed greater cell
growth inhibition in response to ethylhexyl p-methoxycinnamate
(EHMC) and PABA than the other cell lines. The
pretreatment of MM96L with ethidium bromide (EtBr),
which serve as mitochondrial inhibitors, followed by sunscreen
treatment, resulted in apoptosis with increased
uptake of ethidium bromide (12).
When keratinocytes exposed to 5 MED of sunlight were
treated with sunscreen containing ethylhexyl dimethyl PABA
(SPF 15), the number of DNA strand breaks observed here
was at least 75 times higher than that in cells treated with
sunscreen that did not contain ethylhexyl dimethyl PABA
(13).
MCF-7, a human breast cancer cell line, was used to
measure the estrogenic activity of ethylhexyl dimethyl
PABA. Cell proliferation rates were evaluated by attaching
the estrogen receptor of ethylhexyl dimethyl PABA,
and 17β-estradiol was used as a positive control. The EC50
values for cell proliferation were 1.2 pM and 2.63 pM for
17β-estradiol and ethylhexyl dimethyl PABA, respectively


Ethylhexyl dimethyl PABA is an organic derivative of
water-soluble PABA (4-aminobenzoic acid) used as an
ingredient in sunscreen and other cosmetics. Ethylhexyl
dimethyl PABA induced pigmentation of the spleen in a
four-week oral administration toxicity test in rats, and the
NOAEL derived from this study was 100 mg/kg/day. No
significant reproductive toxicity, genotoxicity, carcinogenicity,
skin sensitization, skin irritation, or phototoxicity
was observed in response to ethylhexyl dimethyl PABA
administration. The optimal NOAEL for the risk assessment
was determined to be 100 mg/kg/day based on a
four-week repeated toxicity study in rats. The SED of ethylhexyl
dimethyl PABA was 0.588. The risk characterization
demonstrated that ethylhexyl dimethyl PABA is safe
to use in cosmetics in accordance with current MFDS regulations
because the MOS exceeded 100 even at the maximum
permitted concentration in cosmetics (8%). However,
the toxicological data used in the risk assessment are limited,
and if new toxicological data are reported, further
assessments should be performed as appropriate.

2-Ethylhexyl-4-dimethylaminobenzoate is a chemical primarily used in sunscreens. You have shown a positive allergic reaction to 2-ethylhexyl-4-dimethylaminobenzoate. Avoid contact with this substance.  Here is a partial list of products known to have contained 2-ethylhexyl-4-methylaminobenzoate in the past. To be sure, you should check the contents on the package.

Ethylhexyl dimethyl para-aminobenzoic acid (PABA) is an oily yellow liquid derivative of water-soluble PABA commonly used in sunscreen. Ethylhexyl dimethyl PABA is widely used as an ingredient in many cosmetics at an average concentration of 1.25% (0.5–2.0%) in Korea. Previous studies, including those involving animals, have demonstrated that ethylhexyl dimethyl PABA is toxic to the following four organs: testis, epididymis, spleen, and liver. In addition, experiments using human keratinocytes found that ethylhexyl dimethyl PABA inhibits cell growth and DNA synthesis at low concentrations, and halted the cell cycle of MM96L cells (human melanoma cell line) at the G1 phase. Despite limited clinical data in humans, many studies have confirmed increased mutagenicity of ethylhexyl dimethyl PABA following exposure to sunlight, which suggests that this molecule is likely to contribute to onset of sun-induced cancer despite protecting the skin through absorption of UVB. For risk assessment, the no observed adverse effect level (NOAEL) chosen was 100 mg/kg bw/day in a 4 weeks oral toxicity study. Systemic exposure dosage (SED) was 0.588 mg/kg bw/day for maximum use of ethylhexyl dimethyl PABA in cosmetics. Based on the risk assessment and exposure scenarios conducted in this study, the margin of safety (MOS) was calculated to be 180.18 for a sunscreen containing 8% ethylhexyl dimethyl PABA, which is the maximum level allowed by the relevant domestic authorities.

Padimate O use in dyes and pharmaceutical intermediates. For
the production of reactive red M-80, M-10B, reactive red purple
X-2R and other dyes and the preparation of cyanobenzoic acid
to produce drug p-carboxybenzylamine. Para-aminobenzoic acid
can be used as a sunscreen, and its derivative is octyl
dimethylcarbamate, which is an excellent sunscreen.
Padimate O is an organic compound related to the water-soluble compound PABA (4-aminobenzoic acid) that is used as an ingredient in some sunscreens. This yellowish water-insoluble oily liquid is an ester formed by the condensation of 2-ethylhexanol with dimethylaminobenzoic acid. Other names for padimate O include 2-ethylhexyl 4-dimethylaminobenzoate, Escalol 507, octyldimethyl PABA, and OD-PABA.

  • Share !
E-NEWSLETTER