A hospital has stopped using gas and air in its maternity unit to "protect our midwifery and medical team".
The Princess Alexandra Hospital in Harlow, Essex, said the decision followed tests on nitrous oxide levels.
It said it would temporarily suspend the use of Entonox while additional safety equipment was installed.
Giuseppe Labriola, director of midwifery, said: "There is no risk to mothers, birthing people, their partners and babies."
Other hospitals have previously temporarily suspended the use of gas and air in recent months including Basildon and Ipswich.
Source: BBC News, 22 January 2023