Reports of unusual odours
Today we were in Gloucestershire, where we were asked to carry out an assessment of indoor air quality in relation to chemical contaminants. We were contacted as employees working in the offices had reported smelling unusual odours. The odours reported are described as cigarette smoke-like or acrid, smoke and burn related. The odours are intermittent and occur from one to 14 occasions a day and last for typically no more than several seconds. Employees reported that the odours had been persistent for the last 6 months prior to our assessment.
Fresh air is supplied to the office via a ceiling wide air duct system, with vents spaced approximately every 6 meters. On the day of our assessment the fresh air supply system was fully functional and supplying air under normal conditions. The system consists of several ducts which supply different sections of the office floor. These ducts come from the adjacent building area and terminate in the affected office. Air extraction is provided in the ceiling void.
Testing the air for chemical contaminants
On the day of our assessment, our surveyor noted that the reported odours were not present. However this does not mean that the indoor air quality isn’t chemically contaminated so he begun the sampling process. Using personal samplers fitted with TENAX anasorb thermal absorption tubes and SKC 226-119 tubes, our surveyor collected samples for Volatile organic compounds (VOC) and aldehydes. These samples were collected over a period of two weeks, intermittently and only during times the odours had been reported as being present. We also measured the concentration of carbon dioxide by an IAQ-Cal 7515 direct reading instrument.
Is the indoor air quality chemically contaminated?
Air monitoring revealed that volatile organic compounds were present in the air, although they were at a very low concentration so were not significant for indoor air quality. We believe that these compounds most likely originate from personal care products such as creams, perfumes, hair products and clothing. It is in our surveyor’s opinion that the detected VOCs are unlikely to be the source of the reported odours due to their low concentration. They are also unlikely to cause any irritations health issues.
The samples for carbon dioxide were only marginally above the outdoor environmental background which is indicative that the ventilation within the office space is very efficient and supplies adequate amounts of fresh air into the offices. Therefore we do not believe that carbon dioxide is the source of the reported odours either. We also measured the relative humidity in the office which revealed low humidity. Low relative humidity levels can cause irritation such as itchy eyes, dry mouth and throat therefore if employees start to report such symptoms the humidity is the root cause of this.
On completion of our assessment, our surveyor was happy that the indoor air quality was adequate and no remediation measures were required.