Determination of formaldehyde in air in selected hospital-histopathology laboratories in Cagayan de Oro, Philippines

The study focused on the occupational exposure of gaseous formaldehyde (HCHO) in selected hospital-histopathology laboratories in Cagayan de Oro. This was carried to estimate the potential levels of HCHO during gross-cutting period using absorbent medium between two time intervals. Modified passive sample set-ups of 2,4-dinitrophenylhydrazine (DNPH) and DNPH-coated silica were used for air sample collection between 1 h and 3 h intervals and were analyzed spectrometrically. Infrared (IR) analysis for DNPH-coated silica sample showed relevant peaks of the known IR spectra of formaldehyde hydrazone: 1,600–1,636 cm−1 (CN); 1,000–1,350 cm−1 (CN); 2,945–2,900 cm−1 (aliphatic stretch); 3,218–3,080 cm−1 (NHN); and 880–900 cm−1 (meta disubstituted aromatic). Generally, gaseous HCHO concentrations in three histopathology laboratories during its gross-cutting period exceeded the recommended exposure ceiling limits of American Conference of Industrial Hygienists (ACGIH) and United States Department of Labor-Occupational Safety and Health Administration (USDOL-OSHA) (0.3–0.75 ppm). Absorbing efficiency of DNPH set-up was statistically different from that of DNPH-coated silica set-up. Increased concentration was observed for the 3 h interval using DNPH-coated (0.93 ± 0.32 ppm (Hospital A), 0.80 ± 0.59 ppm (Hospital B), and 1.03 ± 0.36 ppm (Hospital C)). Thus, the installation of exhausts ventilation system was seen necessary to minimize occupational exposure.