At a Seveso-classified chemical plant, an odour of acetic acid was perceptible for several days in the retention pit of the acetic acid/anhydride tank storage area. A worker experienced burns to the respiratory tract. While the product levels remained stable in the storage tanks, the liquid level in the pit rose after pumping. According to the operator, the quantity lost was estimated at 25 t of acetic acid and 14 t of acetic anhydride.
An investigation identified that a drain pipe on an acetic acid storage tank had been pierced and that there was a leak on a joint downstream of the drain valve of an acetic anhydride tank.