Your health DOES matter.....

19 Jan 2016

.......and with that in mind, is it worth wearing ill-fitting face pieces designed to protect you?




Currently, respirators are used to protect workers  and their selection and use are regulated by national legislation.  These requirements include fit test of negative pressure respirator’s mask for each worker - individually.


There are qualitative and quantitative fit test methods (QLFT & QNFT).  The implementation of the requirements of this standard is mandatory for the employer.

Scientific studies have shown that if the mask size and shape better fit to the employees’ face, they will be better protected in the harmful workplaces.


Qualitative fit test methods (QLFT)

These methods use the reaction of workers to the taste or smell of a special material (if it leakage into mask in large degree) - gas, vapors or aerosols, and it helps to detect the presence of gaps. Such reaction is subjective, and it depends on the work reporting results honestly. A qualitative fit test will start with an unfiltered/non-respirator sampling of the mist of choice to verify that the subject can detect the substance of choice. Experts use different types of substances to accomplish the fit testing.

  • Isoamyl acetate - This substance has the smell of bananas. Since vapor can freely penetrate through the surface of the filtering half facepiece respirators, isoamyl acetate is used only for fit testing of elastomeric masks.

  • Saccharin - An aerosol of an aqueous solution of saccharin (Sodium saccharin) is used to fit test both an elastomeric and filtering respirator masks. Saccharin is perceived as sweet taste. The employee should breathe through the mouth, slightly sticking out his tongue. The aerosol is created using a simple aerosol generator with rubber "pear", which is compressed manually.

  • Bitrex - A substance with a bitter taste (Bitrex™) used to detect gaps. It is mixed with water and sprayed in the same manner as the above materials.

Quantitative fit test methods (QNFT)


Using a Portacount to determine the concentrations of particles under the mask and outside the mask, or to determine the flow rate of air flowing under the mask through the gap(s), allows the operator to fit test the mask quantitatively. It is believed that these quantitative methods are more accurate and reliable than qualitative methods.




To give yourself or employees/colleagues piece of mind, we offer face fit testing by a technician deemed "competent" by the BSIF by passing their fit2fit accreditation scheme.  Both Quantitative and qualitative methods are available and even if it is only a question you have at the early stages of ensuring you have the right RPE please