CTC Number is Not the Best Indicator for Odor Control Efficacy
Is the CTC Number the Best Indicator for Measuring the Effectiveness of Odor Control?
When comparing air filtration solutions, the industry standard for measuring the efficacy of activated carbon is the carbon tetrachloride (CTC) number. This number describes the internal porosity of materials which is supposed to be an indicator for how effectively it can trap gases. However, testing shows this number has no direct scientific correlation to removing the broad range of volatile organic compounds (VOCs) commonly-encountered by end-users.
A Better Way to Measure
Purafil is focused on providing filtration solutions that take a holistic approach to improving air quality. In this pursuit, we have found that Toluene testing data is significantly more relevant in describing the VOC adsorption capability of materials. Toluene is an indicator gas for the wide variety of organic contaminants faced in commercial and wastewater gas filtration applications. By testing for adsorption of this aromatic VOC, you can more accurately predict how effectively the filtration media will eliminate odors, a metric certainly more relevant to the customer.
The Science Behind Our Method
Breakthrough results show our new activated carbon product (AC Pellet) has comparable VOC removal performance to carbon products of CTC 50-60 activity. Another interesting takeaway is that higher CTC value carbon can display smaller removal capacities for VOCs than lower CTC carbon which is supported by third-party testing as well. This is because true VOC removal performance depends on other material properties including pore size and carbon type. Overall, the calculated toluene capacity of AC Pellet offers comparable performance to extruded carbon and will often outcompete some carbon adsorbents.