Evaluation of Organic Vapor Adsorption and Filter Performance of Disposable Dust Masks Containing Activated Carbon

Abstract

Objective : Disposable dust masks containing activated carbon in the filtration material are widely used. However, there have only been a few studies of the adsorption of organic compounds by activated carbon in the masks. This study evaluated the effectiveness of organic vapor adsorption (hereafter, breakthrough time, BT) and the filter performance of disposable dust masks containing activated carbon.

Methods : Fourteen types of disposable dust mask containing activated carbon were selected for this study. All masks were certified by the Korea Occupational Health and Safety Agency. Australia and New Zealand standards (AS/NZS 1716, 2003) were applied to determine the BT. The performance of the activated carbon was tested under three different temperature and humidity combinations: room temperature (25±3°C) and no humidity, high temperature (70±3°C) and no humidity, and high temperature (70±3°C) and high humidity (70±10% relative humidity). The masks were assessed against the filter performance safety certification standard for dust masks established by Korean Ministry of Employment and Labor (KMOEL). Results : Only 2 out of 14 (14%) types of mask met the AS/NZ standard. Eight types of mask had a BT of less than 1 min, four of which showed immediate breakthrough. Two types of mask had a BT of over 10 min, and their performance did not change with changes in temperature but decreased drastically with an increase in humidity. When comparing the quality factors (qF) used as a benchmark for filter performance, no discernible changes were observed with changes in temperature and humidity. There was no meaningful correlation between BT and qF standards for pressure drop (PD) and penetration (PN) of filter media. Conclusion : Only 2 of 14 (14%) studied types of disposable dust mask containing activated carbon used in the workplace can effectively remove organic vapors. Hence, most of these types of mask are not appropriate for protecting workers from exposure to organic solvents and gaseous substances. Manufacturers of such masks must provide accurate information regarding organic vapor relief, users must acknowledge the limitations of these products, and the government must establish a precise standard level of organic vapor adsorption for combined dust masks.