The CO2 concentration in over half of the classrooms in the country is higher than recommended by work environment authority Arbejdstilsynet.

The latest report from Danmarks Tekniske Universitet and the Danish Science Factory shows that air quality in the classroom has not improved since 2009.

Teachers' union DLF called the situation “irresponsible” and is encouraging the government to spend more money to clean the air.

However, local government authority KL maintains that enough has been spent already. 

“We have already invested 23 billion kroner in improving the in-school environment,” KL spokesperson Anna Mee Allerslev told DR Nyheder. “I do not know why the environment has not improved.”

READ MORE: Every third Danish school has a poor working environment

Better in Sweden
Swedish law requires mechanical ventilation in classrooms, and while CO2 concentrations are too high in only 16 percent of Swedish classrooms, the numbers are in the red at 60 percent of Danish schools. 

DLF disagreed with Allerslev’s suggestion that the secret was to open windows and air out more often.

“Of course it is up to us to make sure we air out the classrooms, but opening windows alone is not enough,” a DLF safety spokesperson told DR Nyheder.

“A lot of money has been saved lately in the cleaning budget – perhaps some of that could be used to improve the quality of life for students and teachers.”

READ MORE: Class size ceiling will push students into containers

Allerslev insisted that enough had already been spent, and she encouraged schools and her colleagues in the councils around the country to see what else could be done to improve school environments.