Halal foods are foods that are allowed under Islamic dietary guidelines. According to these guidelines gathered from the Quran, Muslim followers cannot consume the following:
A variety of substances are considered as haraam (harmful) for humans to consume and, therefore, forbidden as per various Quranic verses:
• Pork [Quran 2:173]
• Blood [Quran 2:173]
• Animals slaughtered in the name of anyone other than ''Allah''. All that has been dedicated or offered in sacrifice to an idolatrous altar or saint or a person considered to be ''divine'' [Quran 2:173] and [Quran 5:3]
• Carrion (carcasses of dead animals) [Quran 2:173]
• An animal that has been strangled, beaten (to death), killed by a fall, gored (to death), savaged by a beast of prey (unless finished off by a human) [Quran 5:3]
• Food over which Allah’s name is not pronounced [Quran 6:121]
• Alcohol[Quran 5:90]
• These verses also have information regarding halal foods: [Quran 2:173, 5:5, and 6:118-119, 121].
Exception if there is no halal available
If there is absolutely no other food available and one is forced because there is no other choice, then a Muslim is permitted to eat non-halal food. Surah 2:173 states:
۞ إِنَّمَا حَرَّمَ عَلَيۡڪُمُ ٱلۡمَيۡتَةَ وَٱلدَّمَ وَلَحۡمَ ٱلۡخِنزِيرِ وَمَآ أُهِلَّ بِهِۦ لِغَيۡرِ ٱللَّهِۖ فَمَنِ ٱضۡطُرَّ غَيۡرَ بَاغٍ۬ وَلَا عَادٍ۬ فَلَآ إِثۡمَ عَلَيۡهِۚ إِنَّ ٱللَّهَ غَفُورٌ۬ رَّحِيمٌ
He hath forbidden you only carrion, and blood, and swineflesh, and that which hath been immolated to (the name of) any other than Allah. But he who is driven by necessity, neither craving nor transgressing, it is no sin for him. Lo! Allah is Forgiving, Merciful. [Al-Baqara 2:173]
Scientific Reasoning
Attempts have been made to explain or justify some of the prohibitions based on scientific reasoning as follows:
• Carrion and dead animals are unfit for human consumption because the decaying process leads to the formation of chemicals which are harmful to humans
• Blood that is drained from the body contains harmful bacteria, products of metabolism, and toxins
• Swine serves as a vector for pathogenic worms to enter the human body. Infections by Trchinella spiralis and taenia solium are not uncommon. Fatty acids, composition of pork fat have been mentioned as incompatible with human fat and biochemical systems
• Intoxicants are considered harmful for the nervous system, affecting the census and human judgment leading to social and family problems and in many cases even death.
Although these explanations are sound, the underlying principle behind the prohibitions remains the above mentioned Divine orders.
Accordingly, Muslims are permitted all foods, pure and clean for consumption. Islamic Jurisprudence has derived certain principles from the Ahadeeth to determine whether a particular animal or bird is lawful or unlawful.
And Allah (SWT) knows Best!
Source: eat-halal