(CNN) New Zealand has ordered 1,292 square feet of skin to treat patients injured in Monday's volcanic eruption on White Island, authorities said Wednesday.

A total of 47 people were on White Island, off the coast of North Island, when the eruption occurred. Eight people have been confirmed dead, and more than 20 others are currently hospitalized in critical condition. Search and recovery operations are continuing for those still missing and presumed dead on the island.

The skin is now needed to treat patients severely injured by the volcanic ash and gas. On Tuesday, medical officials said 27 people in hospital had burns to at least 30% of their bodies and many have inhalation burns that require airway support. Every burns unit in the country is at full capacity.

"We currently have (skin) supply, but are urgently sourcing additional supplies to meet the demand for dressing and temporary skin grafts," said Peter Watson of the District Health Boards on Wednesday. "We anticipate that we will require an additional 1.2 million square centimeters (1,292 square feet) of skin for the ongoing needs of the patients."

To put that into context, the average human body has about 11 square feet (1 square meter) to 21 square feet (2 square meters) of skin surface area.

The skin order has been placed and will come from the United States, Watson said. Skin and tissue banks from neighboring Australia, like the Donor Tissue Bank of Victoria, are also providing skin grafts and supplies.

The skin grafts come from donors -- like organ donors, skin donors register to donate their skin after death. When skin is donated, usually only a thin layer is taken, like the skin that peels when you are sunburned, according to the Australian government's donation site. The skin grafts are usually taken from donors' backs or the back of their legs.

The demand for skin is particularly high given the unprecedented number of severe burns to the victims, authorities said Wednesday. The patients' burns are already serious from their close proximity to the volcano during the eruption -- but the injuries were also complicated by gases and chemicals, Watson said.

When White Island erupted, there would have been so much poisonous gas released that people would have been able to taste the chemicals, said Jessica Johnson, a volcanologist at the University of East Anglia in England.

The volcano -- which has an acidic lake in its crater -- would also have thrown out boiling hot steam clouds, she added. The patients' severe burns were probably from these steam blasts, she said.

Apart from the steam, they could also have been injured by "very hot rock debris," said Monash University volcanologist Raymond Cas.

These complications meant the patients needed to be rushed to surgical treatment more urgently that with usual burn cases, Watson said on Wednesday, adding, "This is just the start of a very long process that, for some patients, will take several months."

The patients are from a range of nationalities, meaning some of them will be transferred to their home countries for treatment. Australian Prime Minister Scott Morrison said on Wednesday that 10 Australian patients would be repatriated in the next 24 hours to receive "specialist medical care."

Meanwhile, the authorities continue to monitor the volcanic island, which remains too dangerous for rescuers to access. They are also working to identify the six confirmed dead, with the help of forensic pathologists and dentists. Names and faces are beginning to emerge -- an Australian teenager and her stepfather, an Australian mother and daughter, and a New Zealand tour guide are among the victims identified so far.