All perfect praise be to Allah the Lord of the Worlds. May His peace and blessings be upon our Prophet Mohammad and upon all his family and companions.
The majority of the Muslim jurists are of the view that it is forbidden to eat insects because they are disgusting. This is attested to in the following verse: "Those who follow the apostle, the unlettered Prophet, whom they find mentioned in their own (scriptures),- in the law and the Gospel;- for he commands them what is just and forbids them what is evil; he allows them as lawful what is good (and pure) and prohibits them from what is bad (and impure)…." {Al-A`raf, 157}.
An-Nawawi (May Allah have mercy on him) said: "According to our Madhab (Shafie), it is forbidden to eat insects, and this is the view of Abu Hanifah, Ahmad, and Dawoud…….Al-Shafie and his fellow scholars based this view on "and prohibits them from what is bad (and impure)," and for the Arabs, insects are as such. In addition, Narrated `Aisha: The Prophet (PBUH) said, "Five kinds of animals are mischief-doers and can be killed even in the Sanctuary: They are the rat, the scorpion, the kite (a type of predatory bird), the crow, and the rabid dog." {Agreed upon}." {Al-Majmou` Shareh Al-Mohathab, V.9:16}.
As for the materials extracted from insects and transformed- through chemical processes-into other materials, this is called in Islamic Fiqh "Istihalah." It means the change of one substance to another substance, such as transformation of a substance from unclean to clean substance. In scientific terms, it is a chemical reaction that converts compounds into other compounds.
Hanfie jurists stated that impure substances change into pure substances if they are transformed from impurity to purity.
Ibn Humam, a Hanfie jurist, stated: "An example on this is that a sperm-drop is impure, then transforms into leech, which is also impure, then transforms into a clot, which is pure. Another example is that juice is pure, but it can be transformed into wine, which is impure, or vinegar, which is pure." {Fateh Al-Qhadeer, V.1:200}.
Colourants extracted from insects go through several chemical processes to become another substance that gives colour, which makes it edible.
In conclusion, it is permissible to use this colourant (E120), but in line with the following rules:
1-Its properties has changed and transformed into another substance, which is permissible to use.
2-It is used because there is no other alternative.
3-It is used only as needed.
4-It doesn`t harm human health. And Allah the Almighty knows best.