By a referral dated April 24, 2025, the General Directorate for Health (DGS) and the General Directorate for Labour (DGT) jointly requested the High Council for Public Health (HCSP) to update the opinion issued on September 7, 2023, regarding the management of accidents involving exposure to prions and propagons in laboratory settings and during invasive medical procedures, due to the practical complexity of implementing one of its recommendations.

The HCSP adopts the following principles:

a) in the event of an accident involving exposure (AEP) to prions:

• act immediately to limit hemostasis by promoting drainage to remove as much infectious material as possible;
• distinguish between two main types of exposure:
• exposure via skin breach or contact with broken skin, involving the use of bleach (2.6% active chlorine);
• and exposure via splashes onto mucous membranes, involving the use of normal saline or running water.

b) in the event of cutaneous-mucosal exposure to a sample potentially containing propagons:

In cases where the risk associated with propagons is considered high (typically an accident involving exposure to a concentrated solution in a laboratory), and despite bleach lacking neutralizing activity against them, the approach proposed above for ATNCs (unconventional transmissible agents) may still be useful due to its drainage and anti-hemostatic effects in removing the contaminating agent. In cases of exposure without skin breach, the use of detergents validated for skin cleansing is recommended.

In general, the HCSP recommends applying the precautionary principle given current uncertainties regarding the efficacy of the management protocol for such exposure accidents; this strongly underscores the need for essential research to resolve these uncertainties and provide the scientific knowledge required to support relevant expert opinions as a basis for informed decision-making.