Seven people were assessed as a precaution but did not require treatment.
East of England Ambulance Service sent a rapid response vehicle, ambulance crew and ambulance officer to a property on Station Road.
It said they assessed seven people who had headache and sore throat symptoms, believed to have been caused by a cleaning product.
Norfolk fire service said appliances from Massingham, Heacham, Thetford and the enviromental protection unit from Sprowston attended to the smell of gas on Station Road on Monday night.
Crews used a positivie pressure fan to ventilate the property.
A spokesman said the smell was caused by a householder mixing cleaning chemicals.
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