Achieving the balance between user safety and weighing can become a weighty consideration. On the one hand, the impact of air-drafts and ventilation may effect the weighing outcome, and for this reason a lab operator may decide to avoid using balances inside protective devices like fume hoods.  On the other hand, when dealing with chemicals with high OEL (Occupational Exposure Value), the operator may be at risk of extensive exposure to hazardous chemicals, which may affect their health.  The OEL value represents a chemical’s toxicological power and the side effects on human health associated with exposure to that chemical.

How can Erlab Safety Weighing Cabinets protect the user?

Thanks to high filtration efficiency and a solid containment capacity, Erlab Safety Weighing cabinets represent a safe alternative to protect the operator during weighing.

Erlab weighing stations are equipped with 1 or 2 filtration columns which can accept HEPA H 14 or ULPA U16 particulate filters according to EN 1822 for handlings involving powders and/or Molecular filters according to NFX15-211 for experiments involving liquids and gaseous chemicals. In this way, Erlab stations can offer full protection to the operators for both categories of chemicals.


Containment is the capacity of the enclosure to prevent the chemicals released during the experiments from returning to the operator through the front sash. The containment capacity of Erlab weighing Stations has been tested by the American testing company Golder Associate following the testing method defined by the International Society for Pharmaceutical Engineering (ISPE). The results of the test show that < 1 μg is found in front and at different points around Erlab Weighing Station 321 Smart, proving that this model can be used with the most dangerous chemical powders, classified as OEB 5.

What about balance stability and accurate results?

Balances are sensitive tools and personnel working on weighing are aware of the risks of external factors on the accuracy of results. Phenomena like electrostatic forces, environmental vibrations, magnetism effects, evaporation, moisture, can affect the assessment of weighing results. For this reason, many precautions must be taken when using the balance and checking the environment where the handling is performed. Vibration-free and antimagnetic bench, constant room temperature level and relative humidity between 40% or 60% are just few of the common practices followed by chemists during weighing.

Air drafts or ventilation sources can also have negative impact on weighing operation. This concern leads many chemists to avoid using fume hoods as protective safety devices and to perform weighing directly on open benches. Unlike ducted fume hoods, Erlab weighing stations operate with a low volume of air and offer a very smooth airflow inside the enclosure thanks to the large suction area of the filters placed right above the enclosure. Such a smooth airflow and the presence of air foils at the two edges of the front sash opening guaranty a high stability of the balance during weighing operation. Balances with an accuracy of up to 6 digits (-6) can be used in an Erlab weighing stations.

Erlab High precision safety weighing cabinet is the right solution for obtaining user safety without endangering the accuracy of results. They are available in three models: from 800 mm to 1200 mm.