These removal cartridges are pyrotechnic articles of category P2. They make it possible to break a rock thanks to the suppression generated by the pyrotechnic composition which they contain.
At about 12:00 p.m., a blast on a supermarket construction site
caused loud noise, smoke release and the projection of rock debris.
The company in charge of the site was conducting blasts using rock excavation cartridges.
The first two blasts at the site went as planned. When the 3rd blast was fired, rock fragments were violently ejected through a borehole just 60 cm from the cartridge’s location. Hand-size fragments were projected all the way to a bus parking area located on the other side of the road, adjacent to the construction site. Damage was noted on the roof of the depot and on vehicles parked there. No injuries were reported. The manager of the depot filed a complaint, and the construction site was temporarily shut down.
The hole had acted like a cannon. It had been drilled either during a soil study carried out a short time earlier or during a prior intervention of another company involved in the site. The hole was hidden by loose materials and had not been detected before firing the blasting cartridges.
The blast that led to the projections involved two 180-gram cartridges. The workers using the cartridges had been trained in their use by the cartridge supplier that very morning. However, the training programme did not meet regulatory requirements. Rock excavation cartridges are reserved for professional use. Anyone handling these items must be able to prove that they have the required knowledge (certificate of knowledge, authorisation). There are currently 2 approved training centres in France. The supplier of the cartridges is not one of them.
A person authorised to handle these products by another EU Member State is also authorised to handle these products in France. The company in charge of the site plans to send its workers to Spain for cartridge handling training so that the site can resume. Spain is one of the countries where recognised training programmes exist.
For the following blasts, the site manager decided to install vibration sensors. To avoid any projections, the areas concerned are to be secured with metal panels.
