For a while now a new trend has been circulating. It is known as breathable nail polish and many muslim girls say that it is not waterproof and wudhu is permissible with it. Many people follow this and I would like to find out if that is actually the case. Jazakallah
In the Name of Allah, the Most Gracious, the Most Merciful.
As-salāmu ‘alaykum wa-rahmatullāhi wa-barakātuh.
In principle, in order for the Wudhu to be valid the entire limb needs to be washed. This includes the nails as well.
The enamel in conventional nail-polish is impermeable and hence hinders the water from reaching the nails. This means that the primary condition of making the entire limb wet is not fulfilled. The Wudhu’ with such a nail-polish is thus incomplete.
Recently, a couple of cosmetic companies have introduced “breathable” or “water based” nail-polish. Their claim is that the enamel in these nail-polish allows water-vapors to pass through. One such company is “inglot”, which has introduced a range of these “breathable” nail-polishes.
There have been various tests on such nail polishes. However, it is possible that since an individual is unable to do such tests in a control environment, the results can be skewed and inadmissible for reliability. We have thus far come across only one reliable test conducted by Jamiatul Ulama (KZN) of South Africa, on a similar product which claimed to be “Halal nail polish” due to being permeable. Ulama at Jamiatul Ulama concluded:
“The results turned out to be negative and it was concluded that the nail polish is not water permeable and it prevents water from reaching the surface of the nail.”
While we understand the desire of our sisters for a viable alternative to conventional nail-polish, we also iterate that the issue of Wudhu’ is a very important and significant one for our Deen. Wudhu’ is the basic requirement for one of the mightiest worship in Islam, the Salah. If one is not cautious in securing one’s Wudhu’, one would jeopardize this pillar of Islam. The issue of breathable nail-polish directly affects the validity of one’s Wudhu’ and Salah. Hence, caution is extremely important, especially at this stage when we do not have significant number of independent tests which would conclusively prove the permeability of such nail-polish.
It must be noted here that even if according to some tests, water does penetrate the nail polish to some extent, how can one be sure that water reaches the entire nail of every finger? It is known that even if the extent of a pins head is left dry, the Wudhu will be invalid.
Moreover, there is always an option to use henna as an alternative means of beautification. Henna is recommended by Rasulullah Sallallaahu Alahi Wasallam himself, and Wudhu with the henna is also permissible.
And Allah Ta’āla Knows Best
Checked and Approved by,
Mufti Ebrahim Desai.
 الدر المختار وحاشية ابن عابدين (رد المحتار) (1/ 154)
(قَوْلُهُ: بِهِ يُفْتَى) صَرَّحَ بِهِ فِي الْخُلَاصَةِ وَقَالَ: لِأَنَّ الْمَاءَ شَيْءٌ لَطِيفٌ يَصِلُ تَحْتَهُ غَالِبًا اهـ وَيَرُدُّ عَلَيْهِ مَا قَدَّمْنَاهُ آنِفًا وَمُفَادُهُ عَدَمُ الْجَوَازِ إذَا عُلِمَ أَنَّهُ لَمْ يَصِلْ الْمَاءُ تَحْتَهُ، قَالَ فِي الْحِلْيَةِ وَهُوَ أَثْبَتُ.
(قَوْلُهُ: إنْ صُلْبًا) بِضَمِّ الصَّادِ الْمُهْمَلَةِ وَسُكُونِ اللَّامِ وَهُوَ الشَّدِيدُ حِلْيَةٌ: أَيْ إنْ كَانَ مَمْضُوغًا مَضْغًا مُتَأَكِّدًا، بِحَيْثُ تَدَاخَلَتْ أَجْزَاؤُهُ وَصَارَ لَهُ لُزُوجَةٌ وَعِلَاكَةٌ كَالْعَجِينِ شَرْحُ الْمُنْيَةِ.
(قَوْلُهُ: وَهُوَ الْأَصَحُّ) صَرَّحَ بِهِ فِي شَرْحِ الْمُنْيَةِ وَقَالَ لِامْتِنَاعِ نُفُوذِ الْمَاءِ
This answer was collected from Fatwa-tt.com, which is operated by the Darul Iftaa of Jaamia Madinatul Uloom (Trinidad and Tobago) under the advice and guidance of Mufti Ebrahim Desai (Daamat Barakaatuhum) of South Africa.