Question: If one is at the beach and wishes to eat bread but has no water to wash one’s hands with, may one wash one’s hands using the water of the sea or ocean?
Answer: Regarding the laws of washing one’s hands for a bread meal, the Mishnah and Gemara teach us that salty water is invalid for the Mitzvah of Netilat Yadayim. Similarly, water that is so bitter that not even a dog or other animal would drink from it is likewise invalid for Netilat Yadayim. Indeed, the Mishnah in Masechet Yadayim (Chapter 1, Mishnah 3) states that salty water is invalid for Netilat Yadayim. All Poskim, including Maran Ha’Shulchan Aruch (Chapter 160), rule likewise.
It is therefore clear that one may not take a vessel, fill it with water from the sea or ocean, and wash one’s hands with it for a bread meal, for this water is invalid for Netilat Yadayim.
Water with Which Work has been Performed
Water with which work has been performed, such as water which bread was soaked in in order to soften it, water which was used to wash dishes, and the like, is invalid for Netilat Yadayim based on the ruling of Maran Ha’Shulchan Aruch (ibid, Section 2).
Thus, water which was used to wash dishes is invalid for Netilat Yadayim even if the water is still clean and drinkable, for work has been performed with this water.
Sea Water and Sewage Water which have been Desalinated or Treated
Nevertheless, regarding water which has undergone a desalination process by boiling it or filtering it with all sorts of high-tech systems until the water is drinkable as is the case in our days, this water then becomes valid for Netilat Yadayim, for the water is now drinkable.
On the other hand, sewage water that has undergone treatment is nevertheless invalid for Netilat Yadayim even if it becomes drinkable, for the invalidity of this water does not stem from its putrid taste; rather, it is because work has been performed with this water and the treatment process cannot reverse its status, for ultimately, work has been performed with this water. This is based on the guidelines provided in the Responsa Otzarot Yosef (Chapter 7, page 34. The author quotes Hagaon Harav Shmuel Wosner zt”l who rules that if the water was permeated through the ground similar to well-water, this is considered a “new face” for the water and it indeed becomes valid for Netilat Yadayim).
Summary: Sea water is invalid for Netilat Yadayim. In the next Halacha, we shall discuss how one may acceptably purify one’s hands using sea water.