HYDRANAL® Karl Fischer Reagents

New HYDRANAL® classification

Due to new and more stringent evaluations of chemicals by the European Chemicals Agency (ECHA), one of the main components of several HYDRANAL Karl Fischer reagents has been newly classified as a dangerous component. We at Sigma-Aldrich strictly follow our ethical obligations as a responsible supplier and market leader for HYDRANAL Karl Fischer reagents and would therefore like to inform you about new guidelines defining how to safely handle our products.

According to the new European Regulation on Classification, Labeling and Packaging of chemical substances and mixtures (CLP), reagents containing imidazole of 0.3% w/w or more must show the following Pictograms and Hazard statements:1

  GHS08 (Health Hazard)
H360D (May damage the unborn child;

Newly measured values for imidazole concern oral intake of the substance, whereas values for dermal and inhalation remain unchanged. ECHA report on imidazole.

Karl Fischer reagents are handled in closed systems so direct contact with the chemicals is typically prevented and can only occur accidentally. In addition, the reagents contain imidazole only in dissolved and diluted form so risk of exposure to inhalation of powder dust is negligible. The use of personal protection is nevertheless advised, especially the use of gloves to avoid skin contact with the product.

HYDRANAL Karl Fischer reagents contain imidazole in its free form only to a low degree. The amount of free imidazole in the ready-to-use solution 34805 HYDRANAL-Composite 5, for example, is approx. 0.05 mol/L (0.3 %).

We are confident that informing our customers of these changes will help to prevent any incidents. In over 30 years of Karl Fischer titration with HYDRANAL reagents, millions of users have worked with our products and no case of injury has been reported.

Please see below for a list of HYDRANAL reagents for Karl Fischer titration that have been reclassified.


Product No. Brand Description
34805 Fluka HYDRANAL-Composite 5
34806 Fluka HYDRANAL-Composite 2
34827 Fluka HYDRANAL-Composite 1
34816 Fluka HYDRANAL-Composite 5 K
37817 Fluka HYDRANAL-Methanol Rapid
34738 Fluka HYDRANAL-KetoSolver
34800 Fluka HYDRANAL-Solvent
34812 Fluka HYDRANAL-Solvent CM
34730 Fluka HYDRANAL-Solvent E
34749 Fluka HYDRANAL-Solvent Oil
34697 Fluka HYDRANAL-Solver(Crude)Oil
34804 Fluka HYDRANAL-Buffer Acid
34807 Fluka HYDRANAL-Coulomat A
34810 Fluka HYDRANAL-Coulomat AD
34829 Fluka HYDRANAL-Coulomat AF 7
34836 Fluka HYDRANAL-Coulomat AG
34843 Fluka HYDRANAL-Coulomat AG-H
34739 Fluka HYDRANAL-Coulomat AG-Oven
34820 Fluka HYDRANAL-Coulomat AK
34821 Fluka HYDRANAL-Coulomat CG-K
34726 Fluka HYDRANAL-Coulomat E
34868 Fluka HYDRANAL-Coulomat Oil
37858 Fluka HYDRANAL-Moisture Test Kit
37864 Fluka HYDRANAL-Imidazole
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(1) Safety data sheets of all HYDRANAL products are available on our website.