STRATEGY TO EVALUATE THE IMPACT OF FORMALDEHYDE IN ANATOMICAL PATHOLOGY LABORATORY PART III: EQUIVALENCE TEST PROCEDURE FOR AIR MONITORING METHODS

To date, formaldehyde (FA) is one of the more common chemicals and its use is wide-spread around the world in different sectors, especially in chemical facilities and health care. FA is widely used in working activities owing to its chemical and physical properties. However, it also represents a concerning hazard for the workers’ health due to its toxicity and recognized carcinogenicity. The FA exposure evaluation in occupational setting has arisen interest in the scientific community that leads to the development of several analytical instruments in order to assess both long term and short-term exposure. The paper presents and discusses an equivalence tests procedure via the 2.4-dinitrophenylhydrazine (DNPH)-active air sampling formaldehyde (FA) reference method and two non-reference instruments based on continuous, direct reading monitoring, namely ProCeas® (AP2E) and NEMo XT (Ethera). The FA standard atmosphere calibration system was used to check the reference method by Pearson’s test. Subsequently, the Passing-Bablok test was carried out between the non-reference methods and the DNPH method for potential systematic or proportional errors, and finally the Bland-Altman plot was applied to determine the mean bias and the variances of the recorded values by the reference and non-reference methods in on-field sampling. The results showed a good correlation between the non-references method and the DNPH ones, suggesting their possible applications in heterogeneous occupational scenarios.