Residents in Bulmer were evacuated from their homes after a barn fire at Hilltop Farm, which caused a woman to be thrown from her horse.
Firefighters from Suffolk and Essex were called to the blaze on Saturday at around 11.50am.
On arrival, the incident commander requested two additional crews, as well as a water carrier.
Firefighters reported that the blaze in a workshop involved cylinders, gas bottles and a store of petrol.
Police were called to evacuate neighbouring residents and deal with onlookers as the blaze continued to rage.
Wearing breathing apparatus, crews tackled the flames. At 12.10pm, one of the cylinders exploded.
After an hour-and-a-half, the fire was under control, with officers continuing to cool the acetylene and oxygen cylinders.
A joint police and fire investigation has been opened to establish a cause.
At around 12.30pm, as the fire was being tackled, a woman, who was riding on horseback around 500 yards away, was thrown from her horse.
An East of England ambulance, air ambulance and a rapid response team were called. She was taken to West Suffolk Hospital for further treatment.