Is it permissible to enter the restroom if one has in his pocket a small Siddur, Humash or Tehillim, or a page that contains words of Torah? Of course, it is forbidden to bring such materials into a restroom if they are exposed. But is this allowed if one has them in his pocket?
Hacham David Yosef (contemporary), in his Halacha Berura (vol. 3, p. 320; listen to audio recording for precise citation), writes that this is permissible. He explains that since these materials are printed, and not written on parchment, it suffices to simply cover them – such as by placing them in one’s pocket – and they do not require a double covering. He adds that today’s restrooms, with modern plumbing, might not have the same status as restrooms in earlier generations, and so there is greater room leniency.
Although the Mishna Berura (Rav Yisrael Meir Kagan of Radin, 1839-1933) brings (43:25) different opinions in this regard, Hacham David ruled that one may be lenient and enter a restroom with books or pages of Torah literature in his pocket. Hacham David noted that this was the ruling of his father, Hacham Ovadia Yosef, in Yabia Omer (vol. 4, Yoreh De’a, 21).
Summary: It is permissible to enter a restroom with Torah materials – such as a small Humash or pages with Torah articles – in his pocket.