The operators of the Barry Biomass plant have successfully applied to change the way one of the emissions from site is monitored.
This means that they will now check hydrogen fluoride emissions every three months in the first year, instead of continuously.
Natural Resources Wales (NRW) has agreed this change because environmental legislation allows the company to use this method. It emphasises that this will not increase the risk to public health.
This is because emissions of other gases are still monitored continuously, and measures remain in place to make sure levels stay within legal limits.
Any rise in hydrogen fluoride would cause those emissions to rise as well, something the company would have to respond to immediately.
Nadia De Longhi, Operations Manager for Natural Resources Wales said: “We want to reassure people that the change does not affect the safeguards in the environmental permit.
“This type of request is not unusual, and it’s common practice for energy recovery sites in the UK to use this method.
“We will continue regulating the site’s activity as it prepares to begin full operations.”