Gemara

67b (Rav Zutra): If one covers an oil lamp or leaves a kerosene lamp exposed, he transgresses 'Bal Tashchis.' (It causes them to burn faster than necessary.)

129a (R. Chiya bar Avin): If someone let blood and got chilled, we may make a bonfire for him, even in summer [on Shabbos].

They burned a chair of precious wood for Shmuel (after he let blood), a precious table for Rav Yehudah, and a bench for Rabah.

Abaye (to Rabah): You transgress Bal Tashchis!

Rabah: It is preferable not to be wasteful with my health!

140b (Rav Chisda): If someone could eat barley bread, but he eats wheat bread (it is more expensive), he transgresses Bal Tashchis.

Rav Papa: If someone could drink beer, but he drinks wine, he transgresses Bal Tashchis.

Rejection: This is wrong. It is more important not to harm one's body. (Wheat and wine are healthier.)

Kidushin 32a: Rav Huna tore silk in front of his son Rabah, to see if Rabah would get angry.

Question: Rav Huna transgressed Bal Tashchis!

Answer: He tore it at the seams, so it did not depreciate.

Bava Kama 91b (Beraisa - R. Elazar): One who tears too much clothing out of grief over a Mes is lashed for Bal Tashchis.

Inference: All the more so, this applies to damaging one's body!

Rejection: Perhaps damaging one's body is less severe, for the damage can heal, unlike tearing clothing.

Rav Chisda would lift his garment when he walked among thorns, for damage to the body heals, but damage to clothes does not.

Nidah 13a (Mishnah): The more a woman checks herself, the better;

This is forbidden for a man, for it causes emissions. A woman is different, for she is not Bas Hargashah.

Sanhedrin 59b: The Mitzvah to have children was said before Sinai ("Peru u'Rvu") and after ("Shuvu Lachem l'Ohaleichem"), yet it applies only to Yisrael!

Avodah Zarah 11a - Question: When a king dies, we destroy more than just his bed and the Kelim he used!

(Beraisa): We are Oker (cut animals' legs) when the king dies.

Answer (Rav Papa): That refers to the horse he rode on. (It is like a Kli that he used.)

Question: We do this also for Tahor animals (which people do not ride on)!

(Beraisa): Ikur that makes an animal Treifah is forbidden. If it does not make it Treifah, it is permitted.

Answer (Rav Papa): That refers to a calf used to pull a wagon.

Rishonim

The Rif and Rosh (52a and 18:5) bring Rabah's answer to Abaye's question.

Maharsha (Shabbos 129a DH v'Lo): If we make a fire on Shabbos for Piku'ach Nefesh, surely it is not Bal Tashchis! Rather, we discuss making a fire on a weekday. We must delete 'and got chilled' from the text of R. Chiya bar Avin's teaching.

Rif, Rosh and Rambam (Mo'ed Katan 17a, 3:79, and Hilchos Evel 14:24): One who puts too many Kelim on his Mes (this forbids them) transgresses Bal Tashchis.

Rambam (ibid.): We train a person not to be destructive and cast too many Kelim on his Mes. It is better to give them to the poor than to cast them to worms.

Rambam (4:2): One may not bury in silk or golden embroidered shrouds, even the Nasi of Yisrael. It is haughtiness and wasteful and the way of Nochrim.

Rambam (Hilchos Melachim 6:10): One transgresses Lo Tashchis not only for trees. It applies also to one who breaks Kelim, tears clothing, destroys buildings, plugs up springs, or destructively wastes food. He is lashed only mid'Rabanan.

Radvaz: R. Elazar means that one is lashed mid'Rabanan for tearing too much over a Mes. Breaking Kelim is no worse than harming oneself, for which one is exempt.

Note: Tosfos' text (91b DH Over) says that one who tears too much transgressed. It does not say that he is lashed.

Tosfos (13a DH Nashim): R. Tam explains that the three women (for whom pregnancy is dangerous) must use a contraceptive wad at the time of Bi'ah. Other women may do so, for they are not commanded about Peru u'Rvu.. We can explain that our Gemara teaches that the Isur of wasting seed does not apply to women, even if they would emit seed due to sensation. However, even though they are not commanded about Peru u'Rvu, they are equated to men regarding all punishments (so wasting seed should apply to them)! Rather, the Isur does not apply to women because they emit their seed internally, whereas men emit it externally.

Tosfos (Sanhedrin 59b DH v'Ha): What is the source that Nochrim are not commanded about Peru u'Rvu? It is not counted among their seven Mitzvos, but we said (58b) that only Lavim are included in the seven! Really, also Peru u'Rvu is a Lav, for whoever is commanded about Peru u'Rvu is commanded not to waste seed.

Rashba (13a DH Kol): Tosfos says that whoever is commanded about Peru u'Rvu is commanded not to waste seed. This is like he holds in Nidah, that wasting seed does not apply to women. The Ramban asked that even though they are not commanded Peru u'Rvu, they are forbidden to waste seed. All were punished for this in the flood. Even though they have no Isur to castrate, they may not waste seed.

Mishneh l'Melech (Hilchos Melachim 10:7): Perhaps the Rambam holds that Nochrim are commanded Peru u'Rvu not from the verse said to Adam and Chavah, which was merely a Berachah, like the Mizrachi says. Rather, it is due to the verse said to Noach and his sons (Bereishis 9:1). They were commanded only after the flood! However, the Mishnah in Yevamos (65b) proves that Adam was commanded. Rather, the Ramban means that women were punished even though they are not commanded about Peru u'Rvu. Alternatively, he says that according to R. Tam, if women may waste seed because they are not commanded Peru u'Rvu, a Nochri who fulfilled Peru u'Rvu should be permitted to waste seed. Surely there is a limit after which Nochrim fulfilled Peru u'Rvu, just like regarding Yisrael. Rashi (Bereishis 4:24, citing a Medrash) says that Lemech's wives separated from him after they fulfilled Peru u'Rvu. I do not know the source that Nochrim are commanded about wasting seed. Also, why isn't it listed among their seven Mitzvos? This requires investigation.

Aruch l'Ner (13a DH Ke'ilu): The Ramban, Rashba and Ran prove from our Gemara that a woman is commanded about wasting seed, unlike R. Tam, for also women were punished in the flood. Where is the warning not to do so? R. Tam can explain that it is included in Peru u'Rvu [which applies only to men]. How can we answer for those who argue with R. Tam? Even more difficult is to find the source that Yisre'elim are commanded about wasting seed. The Gemara expounds from Lo Sin'af, but this is a mere Asmachta. (The verse forbids adultery.) Perhaps we learn from Bava Kama 91b. Bal Tashchis forbids tearing Kelim, and all the more so wounding oneself. We challenged this, for damage to the body heals, but torn garments do not! Rather, "Asher Chata Al ha'Nefesh" teaches that Bal Tashchis applies to the body. The generation of the flood were punished because Hash-m created the world to be settled, and they did not help do so.

Tosfos (Avodah Zarah 11a DH Ikur): Rashi says that one may not make a Kosher animal Tereifah. This is astounding. It is not Kodshim! If it is due to Bal Tashchis, this applies also to Tamei animals. How did the Gemara know that we discuss a Tahor animal? Also, a Tosefta says that after Ikur one may not eat it, but one may benefit from it. If Ikur does not make it Treifah, one may eat and benefit from it! I.e. 'forbidden' and 'permitted' refer to eating [and not to whether or not Ikur is permitted]. What is the Chidush of the Reisha, that one may not eat a Tereifah? The Chidush is the Heter to benefit from it. Honor of the king does not forbid benefit. Likewise, the Seifa teaches that honor of the king does not forbid eating it.

Poskim

Shulchan Aruch (OC 560:2): In some places, the custom is to break a cup at the time of the Chupah, in order to remember Yerushalayim.

Mishnah Berurah (9): We break an intact cup. Since it is to cause people to put [the Churban] to their heart, it is not Bal Tashchis.

Shulchan Aruch (349:4): One who puts too many Kelim on a Mes transgresses Bal Tashchis.

Nesivos ha'Mishpat (261:1 Bi'urim): If parents were throwing Kelim on the Aron of their child, it is a Mitzvah for others to catch the Kelim before they reach the Aron to prevent Bal Tashchis. Therefore, Yi'ush did not take effect.

Pischei Teshuvah (340:1): One may not tear over a Mes more than required, due to Bal Tashchis.

Magen Avraham (501:13): One may burn a Kli on Yom Tov (for Ochel Nefesh). We must say that he does not have wood, for otherwise he transgresses Bal Tashchis.

Mishnah Berurah (15:3): If Tzitzis are intact and proper to put on another garment, some Acharonim say to untie them and not cut them. One should not spill out his well water if others need it. Chayei Adam says that if the toil of untying them is hard for him, he may cut them. Bal Tashchis does not apply, since he does not do so wastefully.

Taz (YD 117:4): Craftsmen buy skins of big goats only if they were killed through Nechirah, but not if they were slaughtered. One may do Nechirah. It is not Bal Tashchis, like I explained (116:1,6). One may give exposed water to a Tamei animal, for he benefits from this. Semag (Lavin 229) says that whenever the benefit exceeds the destruction, Bal Tashchis does not apply. Tosfos (Avodah Zarah 11a) permits making an animal Tereifah. In Chulin 27b, we permit Nechirah or Ikur to use the blood to dye wool.