Top jurists usually permit industrial and medical alcohol for disinfecting—but the ruling depends on alcohol type, origin and whether it intoxicates, so caution or a local fatwa may still be wise.
This is a practical and important question. In general the fatwas of the marājiʿ differ, but there are common points that help you reach a clearer answer.
Ayatollahs Wahid Khorasani and Sistani, responding to a query about using alcohol as a disinfectant, have considered it ritually pure.
Type of alcohol:
Industrial and medical alcohol: In general many marājiʿ treat industrial and medical alcohol as pure unless there is firm evidence that it is impure.
Intoxicating alcohol: If the alcohol is intoxicating and was originally produced by distilling other substances (i.e., it is derived from fermented/distilled sources), then out of necessary caution it may be considered impure.
Source of the alcohol: If the alcohol is produced from impure materials, even if it is not intoxicating, it is regarded as impure.
Quantity of alcohol: In some instances a very small amount of alcohol mixed into a substance may not itself render that substance impure, depending on juristic criteria.
Opinions of some marājiʿ:
Ayatollahs Sistani and Wahid Khorasani consider alcohol, generally speaking, to be pure (although consuming it is not permitted).
Purification: If the alcohol used is impure, utensils should be washed abundantly with water before use to achieve purification.
Prayer: Praying with hands or clothing contaminated by impure alcohol may invalidate the prayer.
Necessary caution: If you have genuine doubt about an alcohol’s purity, it is better to observe necessary caution and treat it as impure.
In general, using industrial and medical alcohol for disinfection is not problematic provided you can be confident in its purity. For absolute certainty about the ruling that applies to your specific product, consult your own marjaʿ.
Practical tips
Major jurists like Ayatollahs Sistani and Wahid Khorasani regard medical/industrial alcohol as ritually pure, but rulings vary.
If an alcohol is intoxicating or made from impure sources, treat it as impure and avoid relying on it for ritual purity.
When in doubt about a product’s purity, observe caution (iḥtiyāṭ wāǧib) and assume impurity until clarified.
If an object or clothing has been contaminated with impure alcohol, wash it thoroughly with abundant water before prayer.
For a definitive ruling about a specific disinfectant brand or formulation, ask your marjaʿ or local religious authority.
