Praise be to Allah.
Shaykh Ibn ‘Uthaymin (may Allah have mercy on him) said:
“The scholars clearly stated that taking the Mus-haf into bathrooms (toilets) and other unclean places is forbidden, because that is disrespectful towards the Words of Allah. However, if a person fears that it may be stolen if he leaves it outside the bathroom, or he is afraid that he will forget it, then there is no sin on him if he takes it in, because it is essential to protect it.
Tapes are not like Mus-hafs, because tapes do not contain any writing. All that is there is certain vibrations which produce sound when passed through a certain machine. Hence tapes may be taken into the bathroom and there is no problem with that.” (Liqa’at Al-Bab Al-Maftuh, 3/439)
Shaykh Ibn Baz (may Allah have mercy on him) said:
“Entering the bathroom with the Mus-haf is not permissible except in cases of necessity; if one fears that it may be stolen, then there is no sin in that.” (Majmu` Fatawa Ibn Baz, 10/30)
And Allah knows best.