Bionaphtha:

• Naphtha and bionaphtha;
• Legal fictions (mass balance transfer, ethylene pipeline);
• Nishtaneh (machlokes, questions, and answers);
• Masriach, min b'mino, known heter, human intervention;
• Nifsal mei'achilah.

See seforim by Rabbi Cohen at ⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠www.kashrushalacha.com⁠