Introduction: Formaldehyde (FA) compound is a widely used chemical for tissue
preservation in medical histopathology laboratories despite being a probable human
carcinogen and potent irritant. The threshold limit values of air formaldehyde at the
workplace determined by the Occupational Health and Safety (OSHA) organization
is 0.75ppm. Aim of Work: To reduce indoor air formaldehyde levels at the Pathology
laboratory of Kasr Al Ainy hospital to near OSHA permissible levels; as to minimize
health hazards among laboratory healthcare workers. Materials and Methods: An
Interventional Quasi-experimental study using Formaldemeter (Part Per Million
Humidity Temperature Vapor (PPM HTV) apparatus for environmental assessment of
formaldehyde levels before intervention, 6months and 18 months after intervention,
quality control tools were used for risk assessment and action plan intervention, to
change laboratory ( Lab) environment to the safer workplace through separation of each
stage in the lab into 4 stations each had separate ventilation and exhaustion system beside
health education of the laboratory workers. Results: Median values of environmental
Formaldehyde level were higher than recommended permissible level of OSHA at all
stages of the work process in the pathology laboratory which was reduced to nearly half
after the quality control intervention. There was a statistically significant difference in
temperature and humidity between before and after the intervention, the number of airconditioners
and exhaust devices were statistically significant predictors and affecting
factors for environmental FA levels in the lab. Conclusion and Recommendations:
Risk assessment and use of quality control tools to improve the indoor air quality
of pathology laboratory at Kasr Al Ainy hospitals have reduced the environmental
Formaldehyde level to nearly half readings of that before quality intervention after
6 months. Quality control measures include improvement of ventilation systems and   work practices at pathology laboratories with continuous monitoring and maintenance
should be applied to reduce health hazards among laboratory workers.