Dust Collection for Pharmaceutical and Nutraceutical Manufacturing

• Hazardous drugs and chemicals: OSHA classifies drugs as hazardous based on four criteria: 1) genotoxicity; 2) carcinogenicity; 3) reproductive and developmental toxicity; and 4) organ toxicity. Hazardous drugs are regulated by OSHA under the Occupational Exposure to Hazardous Chemicals in Laboratories standard (29 CFR 1910.1450) and the Hazard Communication standard (29 CFR 1910.1200). Under these standards, drug manufacturers may be required to provide toxicity data that can be used to set exposure limits specific to their drug and develop a hazard communication plan that outlines safety procedures and exposure risks for workers.
• Combustible dusts: Combustible dusts are regulated under OSHA’s General Duty Clause (Section 5(a)(1)) with additional requirements under the Hazardous Locations (§1910.307), Hazard Communication (§1910.1200) and Housekeeping (§1910.22) standards. In addition, manufacturers dealing with combustible dusts must follow National Fire Protection Association (NFPA) standards for prevention of fires and explosions. Pharmaceutical and nutraceutical dusts fall under NFPA 654, Standard for the Prevention of Fire and Dust Explosions from the Manufacturing, Processing and Handling of Combustible Particulate Solids. OSHA’s Combustible Dust National Emphasis Program (NEP) outlines policies and procedures for inspecting workplaces that create or handle combustible dusts.

Depending on the hazard level of the dust, mitigation measures may include:

• Engineering controls, such as source capture of dust, industrial ventilation, negative-pressure cabinets and rooms, and other systems to reduce exposure to airborne dusts.
• Personal Protective Equipment (PPE) for workers handling or otherwise directly exposed to hazardous substances, including dusts with APIs. PPE may include face masks or respirators, face shields, gloves, aprons and/or full-body protective gear, depending on the level of hazard.
• Housekeeping and work processes to prevent accumulation of dust and reduce exposure. For example, high-potency pharmaceutical dust may require the use of high-vacuum equipment with HEPA filtration for housekeeping and a “bag-in/bag-out” (BIBO) filter change process for the dust collector to prevent dust from escaping during filter changes.

It is important to note that engineering controls must always be used as a FIRST resort to minimize exposure to dangerous or toxic dust. PPE is used to augment, not replace, engineering control measures.

• Filtration: It is important to use the right filtration system for your dust type. Most pharmaceutical and nutraceutical dusts can be effectively filtered with standard cellulose or nonwoven blend filter media. The “air-to-cloth” ratio (the amount of filter media per CFM of air) of your system will depend on the volume and physical characteristics of your dust. A secondary HEPA filter is recommended for pharmaceutical and nutraceutical dust to remove the last traces of fine particulates. If you are collecting dust that is saturated with water or solvents, you may need a different kind of filter media. Filters with special coatings can reduce entrainment of saturated dusts in the filter media. If dusts are combustible, you will need an anti-static filter media. All filters should have a pulsing system to periodically pulse excess dust off into a collection tray or bin and extend the life of the filters. Processes that produce chemical vapors, gases or VOCs in addition to dust may require a multi-stage filtration system that includes an activated carbon filter to absorb odors, gases and vapors.
• Ductwork and airflow: If you are collecting wet dust, it can help to have a longer system of ductwork between the source and the collector to give it some time to dry out before it hits the filters. You will need to make sure you have enough airflow to keep heavier dusts airborne and prevent them from settling in the ductwork.
• Explosion mitigation: If you are collecting combustible dusts, you will need a deflagration system to reduce the chance of an explosion inside the dust collector and mitigate damage to the facility if an explosion should occur. These systems may include an explosion vent to release built-up pressure in the collector, an isolation valve to prevent pressure waves from propagating back into the facility, and a rotary airlock to keep collected dust safely contained in the hopper.
• Negative pressure systems: Some processes, such as tableting and coating, will benefit from having negative pressure maintained in the room or cabinet where the process takes place. This prevents air from escaping the area under negative pressure, so dust can be more effectively contained and collected.
• High-hazard containment systems: If you are working with dust with active pharmaceutical ingredients (APIs), especially high-potency drugs, standard dust collection and filtration may not be enough. You will also need to have containment systems that prevent dust from escaping the collector during maintenance and filter changes. These may include bag-in/bag-out (BIBO) filter change systems, powder containment systems, full cabinet containment systems for tablet coaters and other types of cabinets, the use HEPA after-filters, negative pressure containment and specialized ductwork to prevent dust from escaping.

Dust collection for pharmaceutical and nutraceutical dust is not “one size fits all.” Our experienced air quality engineers will work with you through the whole process, including needs analysis, system design and engineering, collector and ductwork installation, filter selection, HVAC system integration, startup and commissioning, and aftercare and service.