Determining the biocide content in animal specimens - Investigating the arsenic and mercury contamination of animal specimens at Dübendorf Primary School

The project

Location: Dübendorf, Dübendorf Primary School
Reason: Possible health hazards for teachers and students
Period: September - October 2020


Until the 1980s, animal specimens were treated with arsenic trioxide or compounds containing mercury to protect them from insects. There is therefore a health hazard from arsenic and mercury to teachers and students in schools as a result of touching the specimens or breathing in contaminated dust. In order to create procedures for the storage and handling of these animal specimens, Ecosens AG was tasked with determining the arsenic and mercury contamination of all specimens at Dübendorf Primary School.
Within two days, all 390 specimens were examined using a mobile X-ray fluorescence spectrometer (XRF). The analysis results show that the mercury contamination is negligible, but that most of the specimens are contaminated with arsenic.
A phased approach was created, to differentiate between heavily contaminated and moderately contaminated specimens, based on the detailed measuring data. On the basis of this investigation, Ecosens AG defined measures to ensure safe handling of the specimens with regards to their storage, cleaning and their use in classrooms.


Our services

  • Investigating the animal specimens for arsenic and mercury contamination
  • Collection of measuring data with a mobile X-ray fluorescence spectrometer (XRF)
  • Procedures for the safe handling and storage of animal specimens


  • Cost-efficient performance of the measurements
  • Large number of products
  • No established limits or guidelines to evaluate the arsenic or mercury contamination of animal specimens

Project manager:

Pascal Diefenbacher Divisional manager for indoor air quality
Dr. sc. Environmental Sciences (Federal Institute of Technology) +41 44 839 47 97 More