Experts have been sent to investigate a stench from a waste plant which prompted a raft of complaints from businesses in Leyland.
Companies on Lancashire Enterprise Business Park said the smell coming from the Leyland Waste Technology plant in Farington has been so bad that it has disrupted work outdoors.
Bosses at the £320m recycling plant promised an independent assessor will be sent to look into the problem following several complaints on Thursday.
Darren Platt, depot manager at transport company Pegasus Express, said the smell had been worse than ever in the last few days.
He said: “The stench on Thursday was absolutely horrendous. I’ve got staff that work outside in the yard but it got so bad you could smell it inside the office.
“I’m concerned about hygiene in the long-term - it’s bad for it to pollute this area from that far away. The last time it happened, they were going to change the filters but (the smell) is getting worse again.
“They told us they are aware there is a problem with the smells not dispersing.”
Ongoing issues with smells have also prompted dozens of complaints from residents.
David Brewer, chief executive of Global Renewables Lancashire, pledged last month that additional resources would be brought in to try to tackle the musty stink and that a new team had been set up to investigate odour issues.
A spokesman for Global Renewables said: “Every complaint we have, we do send an independent assessor out.
“They walk round the site and go to the source of the complaint and carry out analysis to find out how intense the smell is.
“It’s a standard practice we carry out. Not every smell comes from here.”
The plant, a private finance initiative with Lancashire County Council, and another Global Renewables base in Thornton treat more than 300,000 tonnes of household waste a year. A community meeting will be held at the Farington plant on March 26.