Answered by Shaykh Shuaib Ally
Question: Assalam alaykum,
Does using oxygen mask, cpap machines or inhalers break the fast? Is it permissible to use intravenous injections for nutritional support or anesthesia?
Answer: Wa alaikum assalam wa rahmatullah,
In the Shafi’i school, inhaling air does not break the fast. Using any of the instruments for inhaling air you’ve mentioned – an oxygen mask, CPAP machine or inhaler – has the same ruling.
Using intravenous injections in the arms or hands for nutritional support or anesthesia also does not render the fast invalid in the school. This is because the legal standard within the school is that the fast is broken by having an object inserted into a body cavity. The arms or legs are not considered body cavities. Hence, an IV would not break the fast.
There are, however, two qualifications to this. The first is that legal validity does not mean that a person should necessarily do this. It goes without saying that hunger is one of the more prominent aspects of fasting; completely circumventing that without cause is contrary to the spirit of the act.
The second is that some recent and prominent scholarship within the school does consider using an IV for nutritional support to render the fast invalid, irrespective of how it enters the body. Muhammad al-Shatiri [Sharh al-Yaqut al-Nafis] and Zayn b. Sumayt [al-Taqrirat al-Sadida] are two examples.
A person should therefore exercise due caution with respect to this issue.