A north-east firm has been told to take action amid fears part of its site poses an explosion risk.
The Health and Safety Executive (HSE) has raised concerns over how biogas is being stored at Sinclair Agricultural and Recycling Services (Sars) in Udny, near Ellon.
It has served the firm with an enforcement notice relating to its anaerobic digestion plant.
This is used to break down waste produce into biogas, which has a number of uses including for renewable heating and power.
HSE says Sars failed to make a “suitable” risk assessment for protecting staff from the flammable and toxic gases the plant can produce.
It criticised a lack of appropriate ventilation, which is needed to prevent the formation of an “explosive atmosphere”, and raised concerns about the spread of any possible fire.
The enforcement notice served on the company reads: “You have failed to provide adequate separation or fire resistance between the biogas storage bag and other hazards (including combustible materials such as woodchip).”
Sars was previously served a notice for the issue in March, and told to remedy the situation by April 14.
This deadline has now been extended until September 7.
The company was contacted for comment.