Assessment of the fit and wearability of commercially available KN95 respirators for children in Indonesia and Nepal

The purpose of this study was to determine how well KN95 respirators, marketed for children, fit the faces of children aged 6–13 years old in two urban sites with elevated levels of air pollution: Kathmandu, Nepal and Bandung, Indonesia. The wearability of the tested respirators and the children's style preferences were also assessed.

Sixty children, 30 in each country, were recruited and were fit tested with three different ear loop respirators in two combinations (with and without an additional adjustable ear loop clip worn around the head). The fit factor for each respirator was determined using a modified fit test protocol for filtering face piece respirators using a TSI PortaCount™ Respirator Fit Tester 8048. Facial dimensions were measured using callipers. The wearability of the respirators and children's style preferences were assessed through questionnaires administered after the fit tests.

Most fit factors were less than 10, i.e. less than 90 % reduction in exposure. In both countries, using an additional ear loop clip was associated with increases in fit factor of 42 and 50 % for Indonesian and Nepalese respirators, respectively. There were no significant differences among the respirators for any of the perceptions: comfort, feeling hot, breathability, fit, embarrassment or appearance for either country. The appearance of the respirator was important to the children. Although the use of an additional ear loop clip improved the fit, the respirators were generally too large for the children's faces to achieve a good fit. Respirators marketed for children should be better designed to suit their facial dimensions.