Application Note – Hygiene N.2 – Environmental Relative Moldiness Index


Environmental Relative Moldiness Index

“ERMI” is the Environmental Relative Moldiness Index, the combination of EPA research and a new method to screen homes for moulds. Based on recently published data from EPA researchers and the 2006 HUD American Healthy Home Survey, the test has been developed as a tool to evaluate the potential risk of indoor mould growth and associated health effects.

This invaluable method provides an objective and standardised system for screening homes for moulds.

The “ERMI” application

The “ERMI” test is used to evaluate the “mouldiness” in any indoor environment and make an assessment of the healthy or unhealthy condition. 

The concentration of different mould species in “mouldy homes” (homes with visible mould growth) and “reference homes” (homes without visible moulds) were compared by the EPA.

Based on these results, mould species were selected and grouped into those with higher concentration in mouldy homes (group 1) and those with lower concentration (group 2).

For the calculation of the ERMI, all concentrations are log-transformed and the sum of group 2 is subtracted from the sum of group 1. The results are obtained in low, moderate or high risk.

Sampling Instructions

(a) Collection of carpet dust samples

(b) Collection of air