370 JOURNAL OF COSMETIC SCIENCE
would demonstrate that liquid water can pass through the nail polish, which could be the
ultimate claim substantiation method of water permeability.
While traditional nail polish meets the needs of most consumer groups, Halal nail polish
was created to cater to Muslim consumers specifically. The key issue regarding nail polish
from an Islamic perspective is the water permeability of the nail polish film. For the daily
prayers required by the Quran to be completed, Muslims must perform Wudu, which is
a ritual purification to clean the body. As discussed in our previous publication7, it is the
general consensus that traditional nail polish does not allow water to come into contact
with the nail and, therefore, invalidates Wudu. The main question of Halal nail polishes
is whether water can permeate the film so that the underlying nail is exposed to water. If
Halal nail polishes are water permeable, they do not need to be removed and reapplied
throughout the day. Aside from the question of how much water is necessary to touch the
nail so that Wudu is considered adequate (something for Muslim scholars to debate), the
key question is how to determine whether the nail polish films are water permeable and to
what extent. Halal nail polishes on the market claim to allow water to penetrate through
the nail polish film and touch the surface of the nail bed. Example claims on marketed
products include “breathable,” “water permeable,” “Wudu-friendly,” and “allows water
molecules to penetrate thought the micro pores without rubbing or added pressure.”8–10
An explanation for water permeability is the existence of the mentioned micro pores in the
resin structure.7
CONCLUSIONS
In this study various methods were used to test the water permeability of two traditional
and three newer nail polishes that claim to form a breathable or water-permeable film.
No strong evidence of water permeation was seen in our study. While nail polish product
offerings are increasing and becoming more diverse to target different needs, testing
methodologies have a long way to come to accurately portray the performance of the
products. This study showed that simple tests often use unrealistic substrates that do not
behave like human nails and the nail polish film does not form evenly on the surface,
therefore, the results are not reliable either. The authors hope that water permeability
method development will accelerate and more reliable tests will be developed for cosmetic
companies interested in these tests.
REFERENCES
(1) 786 Cosmetics. How it works. https://786cosmetics.com/pages/how-it-works 2023.
(2) ASTM D3985-17. Standard Test Method for Oxygen Gas Transmission Rate through Plastic Film and Sheeting
Using a Coulometric Sensor 2017. doi:10.1520/D3985-17
(3) ISO 15105-2:2003. Plastics—Film and Sheeting—Determination of Gas-Transmission Rate— Part 2: Equal-
Pressure Method.
(4) Yam KL, Zhao H, Lai C.C. Frozen food packaging. In: Hui YH, ed. Handbook of Food Science, Technology,
and Engineering. Vol 3. CRC Press 2006:133-5.
(5) Juliano P, Knoerzer K, Sellahewa J, Nguyen MH, Buckow R. Food Engineering Innovations Across the Food
Supply Chain. Academic Press 2022.
would demonstrate that liquid water can pass through the nail polish, which could be the
ultimate claim substantiation method of water permeability.
While traditional nail polish meets the needs of most consumer groups, Halal nail polish
was created to cater to Muslim consumers specifically. The key issue regarding nail polish
from an Islamic perspective is the water permeability of the nail polish film. For the daily
prayers required by the Quran to be completed, Muslims must perform Wudu, which is
a ritual purification to clean the body. As discussed in our previous publication7, it is the
general consensus that traditional nail polish does not allow water to come into contact
with the nail and, therefore, invalidates Wudu. The main question of Halal nail polishes
is whether water can permeate the film so that the underlying nail is exposed to water. If
Halal nail polishes are water permeable, they do not need to be removed and reapplied
throughout the day. Aside from the question of how much water is necessary to touch the
nail so that Wudu is considered adequate (something for Muslim scholars to debate), the
key question is how to determine whether the nail polish films are water permeable and to
what extent. Halal nail polishes on the market claim to allow water to penetrate through
the nail polish film and touch the surface of the nail bed. Example claims on marketed
products include “breathable,” “water permeable,” “Wudu-friendly,” and “allows water
molecules to penetrate thought the micro pores without rubbing or added pressure.”8–10
An explanation for water permeability is the existence of the mentioned micro pores in the
resin structure.7
CONCLUSIONS
In this study various methods were used to test the water permeability of two traditional
and three newer nail polishes that claim to form a breathable or water-permeable film.
No strong evidence of water permeation was seen in our study. While nail polish product
offerings are increasing and becoming more diverse to target different needs, testing
methodologies have a long way to come to accurately portray the performance of the
products. This study showed that simple tests often use unrealistic substrates that do not
behave like human nails and the nail polish film does not form evenly on the surface,
therefore, the results are not reliable either. The authors hope that water permeability
method development will accelerate and more reliable tests will be developed for cosmetic
companies interested in these tests.
REFERENCES
(1) 786 Cosmetics. How it works. https://786cosmetics.com/pages/how-it-works 2023.
(2) ASTM D3985-17. Standard Test Method for Oxygen Gas Transmission Rate through Plastic Film and Sheeting
Using a Coulometric Sensor 2017. doi:10.1520/D3985-17
(3) ISO 15105-2:2003. Plastics—Film and Sheeting—Determination of Gas-Transmission Rate— Part 2: Equal-
Pressure Method.
(4) Yam KL, Zhao H, Lai C.C. Frozen food packaging. In: Hui YH, ed. Handbook of Food Science, Technology,
and Engineering. Vol 3. CRC Press 2006:133-5.
(5) Juliano P, Knoerzer K, Sellahewa J, Nguyen MH, Buckow R. Food Engineering Innovations Across the Food
Supply Chain. Academic Press 2022.
