The Triple S Inspection and Evaluation Rating System for Cleanliness

The TIERS-C system provides a comprehensive tool for assessing and “judging” the overall cleanliness of a building, room, surface or item. While the system will apply slightly differently depending on what is being assessed, the system is based on four color-coded tiers representing a range from clean to unclean or dirty. The four color-coded tiers also correlate to numerical scores ranging from 0-10.

TIERS-C is based primarily on subjective observation — or what one sees, feels,and/or smells. The system; therefore, relies to a certain extent on one’s intuition or “gut.” In some cases, however, objective measurement is recommended; specifically, the use of UV/fluorescent gel marking. ATP meter testing may also be utilized in special cases.**

The four tiers are outlined below. Note that not all descriptions, parameters and metrics will apply to all rooms, surfaces and items.

Green represents the optimal level. The facility, room, surface or item is very clean and in a “like-new” condition.

Blue represents the good/very good level. The facility, room, surface or item is clean although there may be some noticeable signs that it is not optimal.

Yellow represents the fair level. The facility, room, surface or item is best judged as neither trily clean nor really dirty.

Red represents the poor level. The facility, room, surface or item is not clean. It can even be claimed it has been neglected.

**To correlate ATP readings to the TIERS-C system, we recommend using the ISSA Standard for Measuring the Effectiveness of Cleaning in Institutional and Commercial Facilities (0415 2015) or the ISSA Clean Standard (Measuring the Cleanliness of K-12 Schools) (0714-2014). The ISSA Standards are based on three tiers which roughly relate to the Blue, Yellow and Red levels in the TIERS-C system.
See the APPA Five Levels of Clean for reference