Safety in a mine is important where working underground poses many threats. A solution to improve the safety is the use of refuge chambers. The technology and machinery in a mine varies therefore changing the regulations of the design of the refuge chambers to withstand a fire. The purpose of this report is to determine how long it should be possible to maintain a safe environment in the chamber. Today, refuge chambers are produced to meet the different demands from both the customer and current regulations. Since these demands vary the refuge chambers are designed in different ways. A literature study was conducted to find factors that affect the amount of air that is consumed in the refuge chamber. The demands on refuge chambers in Sweden and in some other countries were investigated to check the similarities and differences between them. When the study was finished hand calculations were made on two different fire cases. The calculations were performed for two types of wheel loaders in a mine. The calculations were supposed to show the duration time of a fire. The results from the literature study and hand calculations were later compared and an image of the demands that were necessary was obtained. The factors that were identified as sensitive were air consumption for each person, the function of the air system, psychological effects and the number of people in the refuge chamber. The countries chosen have different regulations and varying approach for use of refuge chambers. The calculations showed that a fire in a vehicle can last for more than seven hours and produce a heat release rate over 15 MW. Many countries take into consideration the aspects that affect the air consumption but Sweden has calculated with the highest air consumption, 20 l air per person and minute. Western Australia is the region which has accounted for the most amounts of factors when determining the time for how long the workers will be able to stay safe inside the chamber. They were also amongst the countries with the longest time for stored air. Table. Time demands on breathable air.Australia-Western Australia 36 hoursCanada – Province of Nova Scotia 8 hoursUK 36 hours is mentioned for one type of chamber.USA 36-48 hoursSweden 4 hoursSignificant differences between the countries’ regulations have been identified. The calculated duration time of more than seven hours for the fire in the vehicle, show that the four hours that are stated in Sweden is not enough. If the risk of explosion and the rescue operation time is considered 36 hours would be more appropriate.