An important issue in analytical laboratories is working safety, because many hazardous materials are used during analytical procedures. Safety aspects for laboratories are described by Hawkins (1988) while Spellman (1997) gives useful advices especially for the environmental laboratory. Moreover, in the "Standard Methods" a chapter about safety in laboratories is contained (Greenberg et al. 1985). Not only work in laboratories is health-threatening, but also sampling of wastewater (Gulyas 1999). First of all, pathogens imply an important risk during sampling. Therefore, measures have to be taken to keep minimum hygienic standards for sampling staff (water-tight gloves, protection clothes only worn in the wastewater-near Environment but not in homes or during meals etc., disinfectants). Small wounds occurring during sampling have to be disinfected at once. Drinking and eating must be avoided during sampling. Moreover, sewers are risky because of the development of toxic gases like H₂S. Therefore, it is dangerous to enter sewers alone and without securing (fixing the person entering the sewer by a rope which is hold tight by a second person outside the sewer giving the possibility to remove the sampling person from the sewer in case of swooning or falling). Another important risk in sewers is the possible generation of methane gas in anaerobic zones. For detecting this gas, carrying along of methane sensors is recommended in sewers. Electrical devices used during sampling (e.g. pumps) must be secure from explosion. When corroding sample preservatives (concentrated acids or alkaline solutions) are used for sample stabilization, goggles must be available on the sampling site. Because of all these reasons, the sampling staff have be instructed concerning safety once a year. Vaccination of the sampling staff against wastewater-born diseases is advisable.