To help astronauts survive the forbidding environment of space, the Apollo spacecraft were designed with many safety features. The command and lunar modules protected the astronauts against such hazards as cosmic radiation, extremes of heat and cold, and micro-meteoroids. The Environmental Control Systems and the Crew Life Support Systems in the spacecraft provided the crews with oxygen, water, and food.
The atmosphere in the Apollo spacecraft was 100% oxygen, at a pressure of five pounds per square inch. The oxygen system constantly added fresh oxygen to the cabin to replenish that breathed by the crew. Carbon dioxide exhaled by the astronauts was removed by canisters of lithium hydroxide.
This canister of LiOH was carried on the Apollo 11 mission and was used to remove Carbon dioxide exhaled by astronauts.
This mask was carried on the Apollo 11 flight and would have been used if smoke or another toxic gas had filled the spacecraft before the astronauts could don their space suits.
Astronauts required water for drinking, washing, and food preparation. Fuels cells in the Apollo spacecraft provided most of the water for astronauts' needs. Fuel cells create electricity by combining hydrogen and oxygen, producing water as a byproduct of this process. A portion of the water supply was chilled for drinking and food preparation. The rest was heated for use in hot meals.
A more sophisticated water system provided both hot and cold water for the preparation of food on Apollo missions. Gemini spacecraft provided only cold water, so all re-hydrated foods on those missions were eaten cold.
Ampules of chlorine (top) were carried on the Apollo 11 flight to prevent the growth of bacteria in the spacecraft water supply.
The ampule's casing (bottom) contained a syringe that periodically injected the chlorine into the water system. After a short time, buffer solution was added to the water in a similar way, which would neutralize the chlorine to make the water safe to drink.