Simply put, biological monitoring is a method of assessing how much of a hazardous substance has been absorbed into the body following exposure, otherwise known as the total body burden of that substance. These are usually urine tests taken at the end of the shift or the working week but occasionally could be blood tests. The advantage of biological monitoring is that it can help to determine absorption through several routes of entry such as by inhalation, ingestion or through the skin. While personal monitoring can give an idea of how much of a substance has been inhaled, this does not factor in other routes of entry. Biological monitoring is therefore a wholesome way of assessing how effective the safety control measures are as well as determining whether particular individuals are not adhering to instruction and advice, often referred to as the ‘dirty worker’ effect, when combined with environmental monitoring. By the same token it can offer the necessary reassurance to employers and employees that the control measures in place are working satisfactorily. Most chemicals covered under the Control of Substances Hazardous to Health (COSHH) Regulations can be tested, particularly solvents, and if you require assistance please contact us at RSOH.