How Should an Aerospace Physician Prepare this Astronaut for the Worst?

Astronaut floating in space

An aerospace physician is faced with a very unusual situation: their patient “may be in contact with fecal matter for up to six days. The patient would be in an extreme survival setting where they would be confined to a survival suit for up to 144 hours.”

The Problem

“The current idea is to have an adhesive fecal bag applied before donning the survival suit. The perianal region would potentially be exposed to feces for the duration of the emergency. We are looking at barrier creams to protect this exposed skin.”

Expanding on the challenges, the aerospace physician shares, “Due to constraints of the survival suit, we can’t use petroleum products and shy away from most ‘natural’ products as they are difficult to quantify the exact contents and thus difficult to determine compatibility with survival systems. We’ve currently narrowed the field to Proshield Plus or Selan + Zinc Oxide. I’m looking for experience with these products, or other ideas for skin protection in this extreme scenario.”

The aerospace physician offered more details and considerations for those helping to brainstorm.

“If the capsule would have a breach due to a meteoroid impact while they are outbound towards the moon, it could take as long as 6 days for them to return, and they would have to be in the suit the entire time. They would have approximately an hour to get into their suits as well as all the other preparations. The suit has restrictions on petroleum products as well as other chemicals that the life support system can’t handle. The crew would be on a regular diet prior to the emergency, and would be on low-residue after entering the suits. Urine can be evacuated from the suit, but feces is much more difficult. A rectal tube won’t work because of the solid feces and comfort.”

Community Input

The community offered some ideas. You can read them all the Figure 1 app.

“I would think that the industrial type barrier creams would be useful in these situations. In the past, to keep paint, grease, dirt from sticking to the skin, I used these products and they did work. Some contained silicone. I have none of these products now but a search should find them.”

Family Medicine Physician

“This is a bit off the wall, from my days as an adhesive and sealant chemist. Consider whether a polyvinyl alcohol coating such as [those] used in teat dips for dairy cattle might be suitable. They are effective in minimizing mastitis in cattle who lie in mud contaminated with feces. Some are fairly moisture resistant, but I don’t know if you’d get 6 days.”


“In lieu of spray on skin (although sounds like the most easily applicable), I’d postulate that a physical barrier to potential bacteria (and an antibacterial gauze or application material to surface) would be the most reliable. I’d recommend research into the type of ‘adult diapers’ used by deep sea divers, due to the similar durations of wear and comparable health concerns.”

Physician Assistant Student

“I’m leaning towards the zinc oxide as a barrier topical. I’d avoid products that contain menthol as these can become irritating. I’ve seen the best protection from the zinc oxide topical. I don’t have as much experience with the proshield plus, however, so I cannot speak towards that. I’m not sure how it works in space, but compounding an antifungal powder into the barrier might help.”


Published October 27, 2021; updated October 3, 2022

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