Activities That Require Netilat Yadayim

1. One should wash netilat yadayim after one: sleeps, goes to the bathroom, touches one's shoes, touches one's legs, touches an area that usually covered, scratches one's head, enters a cemetery.
2. The Shulchan Aruch (4:18) quotes from several rishonim that there is an obligation for one to wash netilas yadayim upon leaving a bathroom even if one did not relieve themselves.
3. The Gemara (Brachos 26a) describes a beis hakisei diParsai, which was a particularly clean bathroom because the waste would roll down to a pit a distance from the actual toilet, and therefore did not have some of the dinim of regular bathrooms. Modern poskim query whether our bathrooms should be treated like a beis hakisei diParai, and thus one would not require netilas yadayim upon exiting them, or not. The Chazon Ish (17:4) leaves this question in doubt, since unlike the bathrooms of the Parsai, in which the waste was removed immediately, our toilets hold the waste for a period of time until it is flushed away. Rav Shlomo Zalman Auerbach (Halichos Shlomo Tefilla 20:24), however, is lenient about this, and the Minchas Yitzchok (teshuva 1:60) concludes that in cases of need (bishas hadchak) one may be lenient not to wash upon leaving our bathrooms.