During the Apollo program, measures were taken to prevent Earth microbes from contaminating the moon, and to prevent hypothetical moon life from infecting the Earth. What were the disinfectants used for these purposes, and were they the same for both purposes?

(Picture of Apollo fecal containment kit. The green packet is a germicidal disinfectant.) Apollo fecal kit

Background info

Section of the Apollo Program Summary Report describes the measures to avoid contaminating the moon, some of which have been popular topics here:

  1. waste products such as feces, urine, and residual food
  2. viable terrestrial micro-organisms released during lunar module depressurization
  3. micro-organisms present in the lunar module waste-water system

Section describes the measures taken to prevent infecting the Earth:

Swimmers assisted the crewmembers in egressing the command module. The swimmers were protected from potential lunar contamination by using their breathing apparatus during installation of the flotation collar on the command module. Furthermore, the swimmers sprayed areas of potential contamination, such as the hatch and docking areas, with a germicidal solution to decontaminate these areas before the hatch was opened.


Upon arrival at the primary recovery vessel, the helicopter was towed close to a mobile quarantine facility and the crewmembers and flight surgeon walked to the facility. The deck area traversed by the crewmembers during the transfer was decontaminated.

... The command module hatch was sealed after egress of the crewmen, and the area surrounding the hatch was decontaminated with a germicide. All decontamination equipment and the life rafts used by the Apollo crewmen were then sunk at sea.


1 Answer 1


Different chemicals were used.

Unless noted, sources are from Biomedical Results of Apollo.

  • Urine and waste-water were held in tanks, passed through an antibacterial filter, and then dumped to the lunar surface.

  • Fecal disposal used a packet of a green germicidal mixture (shown in the picture in the question) of phenols:

    The germicidal liquid was a mixture of sodium orthophenylphenol and sodium chlorophenylphenol of amaplast blue LXT (NASA, c. 1967). The bag was kneaded to rupture the inner pouch and mix the germicide with the wastes.

  • Apollo Experience Report: Food Systems describes the tablet used to decontaminate food waste:

    Each rehydratable package also was provided with a separate com­partment for a germicidal tablet (1 gram of 8-hydroxyquinoline sulfate) for stabilization of uneaten food residue.

  • The initial decontamination of the command module, astronauts, and recovery crew/equipment while they were still in the ocean was by an iodine solution:

    After the crewmen had donned the garments in the spacecraft, they closed the postlanding ventilation system valves. The hatch was then opened and they egressed into the raft which contained a decontaminant solution. The hatch was closed immediately after egress, and the swimmer who had provided the crew with their garments and masks sponged them off with a solution of organic iodine, an antibacterial agent. The spacecraft hatch was also washed down with the solution.

    The Command Module crew was retrieved by helicopter and delivered to the aircraft carrier. The helicopter was then towed to the immediate vicinity of the Mobile Quarantine Facility where the crew left the helicopter and immediately entered the Mobile Quarantine Facility. Following crew egress, the swimmer decontaminated the Command Module, the collar, the raft, and his own protective garment with an antibacterial agent. When the Command Module exterior had been decontaminated, all decontamination equipment and the liferafts used by the Apollo crewmen were sunk at sea.

  • On the deck of the recovery ship, a technician opened the CM, removed samples and data, safely shut-down the CM, and re-sealed the hatch. This technician joined the astronauts in quarantine.

  • After arriving at the Lunar Receiving Laboratory in Houston, the command module was disinfected with formaldehyde:

    Formaldehyde decontamination of the Command Module cabin and suit circuit was accomplished without reopening the hatch. Following a minimum 24-hour kill period, the hatch was opened and the cabin exhausted through the room air conditioning system. The water and waste management systems were also decontaminated with aqueous formaldehyde (formalin) for 24 hours. Spore strips were placed at random locations in the CM to verify decontamination effectiveness.

  • Data tapes were sterilized with ethylene oxide gas:

    Data tapes were received in the CRA and, after appropriate preparation, were sterilized using ethylene oxide gas and passed through the biological barrier. The tapes were then handled using normal procedures.

  • Figure 7 lists other ways that items were decontaminated. This included steam sterilization, dry heat, peracetic acid, hypochlorite (bleach), formaldehyde, ethylene oxide, and holding on to the item until the quarantine was cancelled.

  • All of the sources listed above reference the Contamination Control Handbook. Although not specific to the Apollo program, it is a good general reference on decontamination.

As you can see, the chemicals which were used were not the same.

  • $\begingroup$ Very thorough answer! $\endgroup$ Commented Apr 4, 2020 at 3:29

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