Blue 1 (CI 42090) is generally considered halal as it is derived from synthetic sources and does not contain animal-derived ingredients. However, some brands may use animal-derived ingredients in the production process, which can make it haram.

To ensure it is halal for consumption, it is important to check the source and manufacturer of the product or choose halal-certified products.

And Allah knows best.

Sources:

• Halal Rule
• Ecode Halal Check
• SpecialChem – CI 42090