Powder Handling and Weighing of APIs

The weighing or transfer of powders from one vessel to another, collectively referred to as powder handling, is involved in the production of a variety of products, including cosmetics, foods, beverages, and pharmaceuticals. Within laboratories, powder handling is a nearly ubiquitous task across disciplines, industries, and professions.

Potential Hazards of Powder Handling

Handling powders can be messy and potentially hazardous. Powders, especially fine powders that are easily airborne, can create dust. If inhaled, some chemical powders can cause damage to the nose, mouth, throat, and/or lungs, particularly after large or repeated exposures.

Protection Measures in Powder Handling

Hoods or handling enclosures can provide protection to the operator and others in the powder handling area, promote compliance with chemical standards, and reduce odors. A horizontal laminar flow hood that pulls air from the front of an enclosure to the back can minimize the risk that powder within the hood escapes from the front of the hood near the operator.

Hoods and enclosures with filtration prior to location of air exhaust into the room/environment ensures that powder particles are not released into the surrounding room air and/or environment; protecting both the operator and others in the area. Preventing release of powder particulates into the environment using the appropriate filters and hood design may also help work areas comply with standards for minimizing release of hazardous substances including USP 800. Filters used to capture particulates generated in the hood or enclosure can be removed and disposed of appropriately.

Powder handling within hoods can also minimize nuisance odors to provide a comfortable working environment for all. To provide the most operator protection and reduce nuisance odors, powder handling should be carried out from start to finish within an appropriate hood or enclosure fitted with the appropriate type and number of filters for the type and quantity of powder(s) used. While hoods and enclosures can provide protection, operators should still wear appropriate personal protective equipment (PPE) when working in the hood.

Benefits in Weighing Accuracy

In addition to providing protection from potentially hazardous powders, some hoods or enclosures can provide balance stability for accurate weighing of powders. A hood or enclosure with a horizontal laminar flow can provide airflow to protect the operator, but also creates less turbulence than vertical airflow and prevents small fluctuations in weight due to normal room air circulation. This allows the operator to accurately weigh powders to multiple decimal places.