Résumé : Introductioninformal sector carpenters in Douala, Cameroon, face potential risks to their respiratory health due to daily exposure to fine particles and wood dust. The study aims to demonstrate the importance of preventing respiratory problems in this population through regular use of filtering face pieces (FFP3) respiratory masks.Methodsthe before-after study involved 37 carpenters who wore FFP3 masks during their professional activities for five months. Spirometry measurements were taken before and after the intervention to assess changes in respiratory function.Resultssignificant improvements were observed in forced vital capacity (FVC) 89.6 % to 95.0 % (p<0.000), forced expiratory volume in one second (FEV1) 88.1 % to 95.0 % (p<0.000), Tiffeneau index 82.4 to 84.9 (p<0.000), and peak expiratory flow (PEF) 6.7 l/s to 7.9 l/s (p<0.000) after mask usage, indicating enhanced lung function.Conclusionthe regular use of FFP3 masks had a positive impact on the respiratory health of informal sector carpenters in Douala, enhancing lung function and reducing airway obstruction. The study highlights the importance of preventive measures to safeguard the respiratory well-being of workers exposed to occupational hazards. Spell out Greek characters (i.e: alpha, beta).