What is the actual danger of emergency eyewash stations?

The most important first aid measure for chemical burns, contamination, and eye injuries is immediate rinsing with plenty of water. For this purpose, emergency eyewash stations have been mandatory in laboratories since 1993. Poor maintenance of these can result in the water drawn in an emergency being unhygienic. For this reason, temperating the water above room temperature is also unsuitable. But how likely is the contamination and thus the risk of a microbial infection of the eye? The Institute for Occupational Safety and Health of the German Social Accident Insurance (IFA; formerly BGIA) provides an answer to this question. The Institute for Occupational Safety and Health of the German Social Accident Insurance (IFA; formerly BGIA) examined the microbial load in 30 different emergency eyewash stations and found significant contamination of the rinse water with microorganisms in 80% of cases (55,000 colony-forming units (CFU) per mL). The presence of Pseudomonas aeruginosa in twelve cases played a particularly decisive role, as this type of bacteria can damage the eye and even lead to blindness. However, despite the detection of various amoeba species, no pathogenic Acanthamoeba could be detected. These can penetrate deep into the cornea if the eye is injured and cause infections that are difficult to treat. Less severe bacterial contamination was detected in a follow-up project by the IFA in cooperation with the State Institute for Occupational Safety and Health of North Rhine-Westphalia (LAfA NRW) and the Employers' Accident Insurance Association of the Chemical Industry (BG Chemie). For this purpose, water samples were taken immediately after activation and after three minutes of operation, and the CFU value was determined. Neither P. aeruginosa nor Acanthamoeba were detectable in any of the samples, and the maximum bacterial contamination was also a maximum of 3,000 CFU per mL. However, it was shown that consistently higher bacterial contamination was detected after the first activation than after three minutes of rinsing. In principle, hose-free systems also have lower germ loads than one-hand systems equipped with flexible hoses. This is possibly due to the easier formation of a biofilm in the hoses. In contrast, the germ load is independent of the age of the installed emergency eyewash station. Based on the measurement results obtained, the IFA therefore recommends, in addition to the monthly functional test , that the emergency eyewash stations be operated for one minute every day if possible, that the hoses of flexible systems be replaced annually and that they be kept as short as possible (1.5 to 2 m). During installation, care must be taken to ensure that the supply lines are not designed as branch lines. Annual testing for the presence of P. aeruginosa is also recommended.