This story aired in the following known countries. They are listed in chronological order according to known airdate. If no month is noted, the actual airdate is not confirmed, and is a close approximate. (Refer also to Selling Doctor Who for expanded airdates.)
- The story was assessed and rejected by the censors in Australia in October 1973. This also meant New Zealand, Hong Kong, Singapore and Gibraltar could not purchase.
- The story was also not offered to Middle Eastern countries, so i didn't air in Saudi Arabia or United Arab Emirates. It is thought this might have been because the serial did not paint the oil/chemical industry in a very good light...
- The Australian censors were asked by the ABC to reassess the story for a run of repeats, and it was cleared.
- The story was also picked up by New Zealand a year later.
- It was released to the USA in 1983, and again in 1985. Canada was also offered the serial again.