In hospitals, the chemical formaldehyde is commonly utilised to preserve tissues. The healthcare personnel exposed to formaldehyde the most work in histopathology laboratories. This study aims to determine the health effects of everyday formaldehyde exposure on healthcare professionals in the histopathology laboratory. Cross-sectional comparative research was used for the study design. The 8-hour time-weighted-average (TWA₈) formaldehyde level was measured at the histopathology laboratory at Hospital Queen Elizabeth in Sabah and the administration office (control) using the real-time colorimetric tube method. Workers in both places were required to answer a questionnaire on their health status. The TWA₈ formaldehyde level was higher in the exposed area (0.113 ppm) than in the unexposed area (0.031 ppm). Air samplings showed that formaldehyde exposure levels in the exposed area (0.108 ± 0.026 ppm) were significantly higher than in an unexposed area (0.028 ± 0.018 ppm) at p < 0.001. Symptoms closely related to formaldehyde exposure were 51% in the histopathology laboratory workers, greater than 35% in the control group (p < 0.05). The workers showed six symptoms: irritated eyes, sore throat, cough, runny nose, sneezing and headache. Although the level of occupational workplace exposure to formaldehyde in the histopathology laboratory was below the recommended limit, the health symptoms related to formaldehyde among the exposed group were detected. Enhancing control measures for indoor air quality improvement in the working area is required to minimise the health risk among laboratory workers.

• Ahmed, H. O. (2011). Preliminary study: Formaldehyde exposure in laboratories of Sharjah University in UAE. Indian Journal of Occupational and Environmental Medicine, 15(1), 33-37. https://doi.org/10.4103/0019-5278.82997

• Amoore, J. E., & Hautala, E. (1983). Odor as an aid to chemical safety: Odor thresholds compared with threshold limit values and volatilities for 214 industrial chemicals in air and water dilution. Journal of Applied Toxicology, 3(6), 272-290. https://doi.org/10.1002/JAT.2550030603

• Azari, M., Asadi, P., Jafari, M., Soori, H., & Hosseini, V. (2012). Occupational exposure of a medical school staff to formaldehyde in Tehran. Tanaffos, 11(3), 36-41.

• Binawara, B. K., Rajnee., Choudhary, S., Mathur, K. C., Sharma, H., & Goyal, K. (2010). Acute effect of formalin on pulmonary function tests in medical students. Pakistan Journal of Physiology, 6(2), 8-10.

• Bono, R., Romanazzi, V., Pirro, V., Degan, R., Pignata, C., Suppo, E., Pazzi, M., & Vincenti, M. (2012). Formaldehyde and tobacco smoke as alkylating agents: The formation of N-methylenvaline in pathologists and in plastic laminate workers. Science of the Total Environment, 414, 701-707. https://doi.org/10.1016/j.scitotenv.2011.10.047

• Clerc, F., Emili, A., & Mater, G. (2020). AltrexChimie, a web application for the management and the interpretation of occupational exposure measurements to chemical substances. International Journal of Environmental Research and Public Health, 17(10), Article 3375. https://doi.org/10.3390/IJERPH17103375

• Du, Z., Mo, J., Zhang, Y., & Xu, Q. (2014). Benzene, toluene and xylenes in newly renovated homes and associated health risk in Guangzhou, China. Building and Environment, 72, 75-81. https://doi.org/10.1016/J.BUILDENV.2013.10.013

• Elshaer, N. S. M., & Mahmoud, M. A. E. (2017). Toxic effects of formalin-treated cadaver on medical students, staff members, and workers in the Alexandria Faculty of Medicine. Alexandria Journal of Medicine 53(4), 337-343. https://doi.org/10.1016/j.ajme.2016.11.006

• Ghasemkhani, M., Jahanpeyma, F., & Azam, K. (2005). Formaldehyde exposure in some educational hospitals of Tehran. Industrial Health, 43(4), 703-707. https://doi.org/10.2486/indhealth.43.703

• Hauptmann, M., Stewart, P. A., Lubin, J. H., Freeman, A. E. B., Hornung, R. W., Herrick, R. F., Hoover, R. N., Fraumeni, J. F., Blair Jr, A., & Hayes, R. B. (2009). Mortality from lymphohematopoietic malignancies and brain cancer among embalmers exposed to formaldehyde. Journal of the National Cancer Institute, 101(24), 1696-1708. https://doi.org/10.1093/jnci/djp416

• Jerusalem, J. G., & Galarpe, V. R. K. R. (2015). Determination of formaldehyde in air in selected hospital-histopathology laboratories in Cagayan de Oro, Philippines. Journal of Chemical Health and Safety, 22(1), 10-14. https://doi.org/10.1016/j.jchas.2014.07.012

• Kim, K. H., Jahan, S. A., & Lee, J. T. (2011). Exposure to formaldehyde and its potential human health Hazards. Journal of Environmental Science and Health - Part C Environmental Carcinogenesis and Ecotoxicology Reviews, 29(4), 277-299. https://doi.org/10.1080/10590501.2011.629972

• Ladeira, C., Viegas, S., Carolino, E., Prista, J., Gomes, M. C., & Brito, M. (2011). Genotoxicity biomarkers in occupational exposure to formaldehyde-The case of histopathology laboratories. Mutation Research - Genetic Toxicology and Environmental Mutagenesis, 721(1), 15-20. https://doi.org/10.1016/j.mrgentox.2010.11.015

• Malaysia DOSH. (2000). Malaysia Occupational Safety and Health Act and Regulations Act 514 (1994) Use and Standards of Exposure of Chemicals Hazardous to Health Regulations 2000. Malaysia DOSH. https://www.dosh.gov.my/index.php/legislation/regulations/regulations-under-occupational-safety-and-health-act-1994-act-514/522-pua-131-2000-1/file

• Malaysia DOSH. (2018). Assessment of the health risk arising from the use of chemicals hazardous to health at the workplace. Malaysia DOSH. https://www.dosh.gov.my/index.php/legislation/guidelines/chemical/2874-01-a-manual-of-recommended-practice-on-assessment-of-the-health-risks-arising-from-the-use-of-chemicals-hazardous-to-health-at-the-workplace-3rd-edition/file

• Ministry of Human Resources Malaysia (2010). Questionnaire for building occupants. In Industry Code of Practice on Indoor Air (pp. 36-38). Department of Occupational Safety and Health.

• MOH. (2010). Guidelines on chemical management in health care facilities Ministry of Health. MOH. https://www.moh.gov.my/moh/images/gallery/Garispanduan/Guidelines_on_Chemical-1.pdf

• Motta, O., Charlier, B., De Caro, F., Coglianese, A., De Rosa, F., Moccia, G., Pironti, C., Capunzo, M., Borrelli, A., Filippelli, A., & Izzo, V. (2021). Environmental and biological monitoring of formaldehyde inside a hospital setting: A combined approach to manage chemical risk in workplaces. Journal of Public Health Research, 10(1), jphr.2021.2012. https://doi.org/10.4081/JPHR.2021.2012

• Norbäck, D., Hashim, J., Hashim, Z., & Ali, F. (2017). Volatile organic compounds (VOC), formaldehyde and nitrogen dioxide (NO2) in schools in Johor Bahru, Malaysia: Associations with rhinitis, ocular, throat and dermal symptoms, headache and fatigue. The Science of the Total Environment, 592, 153-160. https://doi.org/10.1016/J.SCITOTENV.2017.02.215

• Ogawa, M., Kabe, I., Terauchi, Y., & Tanaka, S. (2019). A strategy for the reduction of formaldehyde concentration in a hospital pathology laboratory. Journal of Occupational Health, 61(1), 135-142. https://doi.org/10.1002/1348-9585.12018

• Orsière, T., Sari-Minodier, I., Iarmarcovai, G., & Botta, A. (2006). Genotoxic risk assessment of pathology and anatomy laboratory workers exposed to formaldehyde by use of personal air sampling and analysis of DNA damage in peripheral lymphocytes. Mutation Research - Genetic Toxicology and Environmental Mutagenesis, 605(1-2), 30-41. https://doi.org/10.1016/j.mrgentox.2006.01.006

• Parikh, J., Ly, L., & Tkaczuk, M. (2009, December 5-9). Respirable quartz exposure monitoring in South Australian quarries. [Paper presentation]. AIOH2009 Conference, Canberra, Australia.

• Salthammer, T., Mentese, S., & Marutzky, R. (2010). Formaldehyde in the Indoor Environment. Chemical Reviews, 110(4), 2536-2572. https://doi.org/10.1021/CR800399G

• Takahashi, S., Tsuji, K., Fujii, K., Okazaki, F., Takigawa, T., Ohtsuka, A., & Iwatsuki, K. (2007). Prospective study of clinical symptoms and skin test reactions in medical students exposed to formaldehyde gas. The Journal of Dermatology, 34(5), 283-289. https://doi.org/10.1111/j.1346-8138.2007.00274.x

• USDOL. (2021). 1910.1048 App C - Medical surveillance - Formaldehyde | Occupational safety and health administration. US OSHA Official Website. https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1048AppC

• Viegas, S., Ladeira, C., Nunes, C., Malta-Vacas, J., Gomes, M., Brito, M., Mendonça, P., & Prista, J. (2010). Genotoxic effects in occupational exposure to formaldehyde: A study in anatomy and pathology laboratories and formaldehyde-resins production. Journal of Occupational Medicine and Toxicology, 5(1), 1-8. https://doi.org/10.1186/1745-6673-5-25

• WHO. (2000). Chapter 5.8 formaldehyde. In Air quality guidelines for Europe (2nd ed., pp.87-91). WHO Regional Publication.

• WHO. (2010). WHO guidelines for indoor air quality: Selected pollutants. WHO Regional Office for Europe. http://www.who.int/iris/handle/10665/260127

• Xu, W., & Stewart, E. J. (2016). A comparison of engineering controls for formaldehyde exposure during grossing activities in health care anatomic pathology laboratories. Journal of Occupational and Environmental Hygiene, 13(7), 529-537. https://doi.org/10.1080/15459624.2016.1149182

• Xu, Y., & Zhang, Y. (2003). An improved mass transfer based model for analyzing VOC emissions from building materials. Atmospheric Environment, 37(18), 2497-2505. https://doi.org/10.1016/S1352-2310(03)00160-2

• Ya’acob, S. J., Suis, A. J., Awang, N., & Sahani, M. (2013). Exposure assessment of formaldehyde and its symptoms among anatomy laboratory workers and medical students. Asian Journal of Applied Sciences, 6(1), 50-55. https://doi.org/10.3923/ajaps.2013.50.55

• Zain, S. M. S. M., Azmi, W. N. F. W., Veloo, Y., & Shaharudin, R. (2019). Formaldehyde exposure, health symptoms and risk assessment among hospital workers in Malaysia. Journal of Environmental Protection, 10(06), 861-879. https://doi.org/10.4236/jep.2019.106051