UD11 Biogaval. Riesgo biológico

Biological Risk Assessment in Work Activities

Overview of the Practical Manual

• The session discusses a practical manual for assessing biological risk in various work activities, published in 2004 and named Biogabal. This manual provides a methodology to quantify and evaluate exposure to biological agents according to Royal Decree 664-1997.

Updates and Methodology Simplification

• In 2010, the manual was revised, and by 2013, a simplification of the methodology was introduced. This involved applying the method specifically to microorganisms that are commonly encountered during evaluations and represent frequent damage.

• The methodology is applicable only in scenarios without deliberate manipulation of biological agents, such as wastewater treatment, waste disposal, animal contact work, food production centers, agricultural tasks, or healthcare assistance.

Calculating Biological Risk Level

• The method involves obtaining a numerical value for the biological risk level (R) for each microorganism at the workplace based on variables: damage potential, vaccination status, transmission routes, incidence rate, and task frequency. Values Dd and Dt can be adjusted based on hygiene measures implemented.

• The calculated risk level is compared against reference values: an action level of 12 and an exposure limit of 17; R must not exceed 17. Identification of biological agents present at the workplace is crucial as outlined in Annex 1 tables within the document.

Evaluating Key Variables

• After identifying microorganisms for evaluation:

• Each microorganism's variables (damage potential, vaccination status, transmission routes) must be scored from tables providing scores between one to five.

• These scores are then substituted into formulas to calculate overall risk levels.

Damage Potential Scoring

• Damage scoring ranges from 1 to 5 based on temporary incapacity days and whether there are lasting effects; e.g., varicella has a score of 1 due to less than 30 days incapacity with no sequelae.

Transmission Routes Scoring

• Transmission scoring varies:

• Direct transmission = score of 1,

• Indirect transmission through contaminated materials or vectors = score of 1,

• Airborne transmission via aerosols = score of 3.

• For varicella which transmits through all three routes combined scoring results in a total transmission value of 5.

Incidence Rate & Vaccination Scoring

• Incidence rate derived from new cases over the previous year yields scores; e.g., if there were 200 cases last year = score of 4.

• Vaccination percentage among workers affects scoring; e.g., if vaccinated workers constitute 80%, it results in a score of 2.

Frequency & Hygiene Measures Evaluation

• Frequency indicates exposure time expressed as a percentage; e.g., if exposed for half their working hours (50%), this corresponds to a score of 3.

• Hygiene measures taken at work are assessed using affirmative responses counted against total measures adopted leading to further adjustments in scores based on percentages obtained from these responses (e.g., >94% affirmative leads to subtracting two).

Final Calculation Adjustments

• DEIT values cannot fall below one; thus adjustments ensure they remain valid.

• For example: Varicella’s damage remains at one after adjustment while its transmission drops from five down to three post-hygiene measure correction leading towards final calculations yielding an overall risk value aligning with action levels established earlier (12).