Derby Crown Court heard that the employee was emptying waste dust from the machine’s hopper into a bag at Tarmac’s Swadlincote plant last September.
Each bag holds approximately 750kg of dust. If the side of the bag folds in then the dust will follow the crease in the bag and spill onto the floor. To avoid this, the 45-year-old, from Coalville, would periodically lift the sides of the bag. He was standing with his feet in the gaps of the pallet the bag was on and attempted to lift the sides of the bags but lost his balance and fell forwards.
As he put his hand out to stop his fall it landed on the hopper and three of the fingers of his right hand went into it, coming into contact with the rotary valve. He was off work for nine months.
A Health & Safety Executive (HSE) investigation found that the dust extraction unit originally had a fully-enclosed recycling system where waste dust was blown back into a silo to be reused. But earlier in 2012 a section from underneath the hopper was removed to try to solve a contamination problem, which enabled access to the rotary valve.
Tarmac Building Products Ltd, of Millfields Road, Ettingshall, Wolverhampton, pleaded guilty to a breach of Regulation 11(1) of the Provision and Use of Work Equipment Regulations 1998 and was fined £30,000 and ordered to pay £4,999 in costs.
Speaking after the hearing, HSE inspector Edward Walker said: "This incident could easily have been avoided had an appropriate guard been fitted when the hopper was modified. When modifying machinery and equipment it is important to make a suitable assessment of any increased risk that changes may cause. Tarmac Building Products failed to do that and a man was left with a permanent impairment."