Biological (or toxicokinetic) monitoring is the measurement of a chemical or its metabolites in body fluids (exhaled air, blood, urine) in order to assess its absorption by all routes (inhalation, ingestion, dermal) from both occupational and non-occupational sources of exposure. Organic solvents such as benzene and metals such as lead, arsenic, and chromium are eligible for biological monitoring.

Biological monitoring can be considered when:
absorption of the chemical occurs through skin contact or ingestion, or heavy exertion increases inhalational absorption
air testing indicates exposure above the occupational exposure limit (OEL) and
a measure of the effectiveness of exposure controls is needed
required by provincial or federal regulations.

Biological monitoring can be considered when:
⦁ absorption of the chemical occurs through skin contact or ingestion, or heavy exertion increases inhalational absorption
⦁ air testing indicates exposure above the occupational exposure limit (OEL) and
a measure of the effectiveness of exposure controls is needed
⦁ required by provincial or federal regulations.

Key challenges in the development of a biological monitoring program are:

⦁ The key question: how will biological monitoring contribute to the assessment of exposure?
⦁ Do your toxicology homework – has testing been validated for your specific industrial process? What community, workplace, and toxicity threshold values will be used for the interpretation of results?
⦁ Review sample collection, transport, analysis, and interpretation issues with an accredited laboratory
⦁ Procedure and health questionnaire development
⦁ Education, enrollment, and notification of employees