Introduction to Dust Control for the Pharmaceutical and Nutraceutical Industries
Manufacturing solid and powdered drugs, vitamins and nutraceuticals can create quite a bit of dust. Depending on the ingredients and processes you are using, this dust may be hazardous, combustible and/or toxic. Pharmaceutical and nutraceutical production requires effective dust collection to reduce risks to workers, comply with regulatory requirements and prevent cross-contamination within the facility.
All types of pharmaceutical and nutraceutical production create air quality concerns, but dust control is especially important for solid dosage processes, including production of tablets, powders and powder-filled capsules. Uncontrolled pharmaceutical and nutraceutical dust can contaminate processes and create health hazards for workers.
DUST-CREATING PROCESSES IN PHARMACEUTICAL AND NUTRACEUTICAL PRODUCTION
There are many different solid dosage processes, each with their own dust-creation concerns. Some of these processes include:
DUST COLLECTION CHALLENGES FOR THE PHARMACEUTICAL AND NUTRACEUTICAL INDUSTRIES
The pharmaceutical and nutraceutical industries face several challenges when it comes to dust control. The exact risks and challenges depend on the ingredients and processes used.
Nuisance dust: Many of the dusts created in the production of vitamins, protein powders and other nutraceuticals are not especially toxic or dangerous, but that doesn’t mean dust control isn’t important. Nutraceutical dust can still create health problems—such as lung irritation and aggravation of asthma symptoms—when inhaled. Some nutraceuticals can also trigger allergic reactions in susceptible employees, which can get worse over time with continued exposure. Uncontrolled dust of any type is also a housekeeping and sanitation consideration.
Hazardous/high-potency pharmaceutical dust: If manufacturing processes create dust with Active Pharmaceutical Ingredients (APIs), more stringent controls will be needed to prevent workers from being exposed. Many pharmaceutical dusts are toxic when inhaled, even in small quantities. And any exposure to medications outside of the normal doctor-prescribed channels is a health concern for employees. Employees exposed to uncontrolled pharmaceutical dusts may have significant side effects, interactions with drugs they are taking, or dangerous allergic reactions. High-potency drugs may require extra-special care to prevent both inhalation and exposure to skin and mucus membranes, even in small amounts.
Water vapor or solvents: Some pharmaceutical compounding and manufacturing processes create water vapor, solvent vapor or moisture-laden dusts. This can create special challenges in dust collection. Hygroscopic dusts absorb moisture in the air that makes them heavier and stickier. These dusts are harder to pulse off of filters and can cause excessive filter clogging.
Combustible dusts: Many of the dusts created by pharmaceutical and nutraceutical production are highly combustible. That means they can generate an explosion when allowed to concentrate in the air or inside a dust collection machine. Special care must be taken when collecting combustible dusts to minimize the risks of an explosion inside the dust collector.
Cross-contamination concerns: Cross-contamination is a particular concern in the pharmaceutical and nutraceutical industries. Dust that is not properly controlled may escape enclosures and contaminate other production lines. This can lead to sanitation and safety concerns, including the risk of dangerous allergic reactions from cross-contamination.
DUST CONTROL REGULATIONS FOR THE PHARMACEUTICAL AND NUTRACEUTICAL INDUSTRIES
The pharmaceutical and nutraceutical industries are highly regulated, with many different standards for every stage of the production process, from sanitizing to packaging. The most relevant regulations for dust control fall into one of two categories: nuisance dusts and hazardous chemicals. Pharmaceutical and nutraceutical manufacturers also have to follow OSHA and NFPA standards for combustible dusts.
Nuisance dusts: Many nutraceutical dusts fall under the OSHA definition of “nuisance dusts,” which are regulated under the general particulate matter concentration limits set by OSHA. The general limit for “Particulates Not Otherwise Regulated” (PNOLs) is 15 mg/m3 (8-hour TWA limit) for total particulate and 5 mg/m3 for respirable particulates. Employers must also follow general Housekeeping standards (OSHA 1910.22, Walking-Working Surfaces) to prevent accumulation of dust on surfaces.
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.
CONSIDERATIONS IN SELECTING A DUST CONTROL SOLUTION FOR PHARMACEUTICAL AND NUTRACEUTICAL DUST
When designing a dust control solution for pharmaceutical and nutraceutical dusts, engineers will take several factors into consideration. Questions include:
What are the human health hazards associated with the dust? Does it contain an API? What is the PEL for the dust?
What are the physical characteristics of the dust? How much dust is produced?
Does the process keep dust fairly contained (such as in a hood or cabinet), or is it more open?
Is the dust combustible? What are the combustion risks present in the environment in which it is produced?
What is the moisture level of the dust? Are water vapor or solvents present in the air?
Does the process produce dangerous chemical vapors, gases or volatile organic compounds (VOCs) that must be controlled along with the dust?
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.
DUST CONTROL SOLUTIONS FOR THE PHARMACEUTICAL AND NUTRACEUTICAL INDUSTRIES
RoboVent offers robust and innovative dust, fume and odor collection solutions for the vitamin, nutraceutical and low-potency pharmaceutical industries.
Dust control solutions for pharmaceutical and nutraceutical dusts may have several elements.
Source capture: It is usually best to capture pharmaceutical and nutraceutical dust as close to the source as possible to prevent propagation throughout the facility. Processes that can be enclosed under a hood or in a cabinet can be ducted directly to a dust collector for efficient source capture and filtration.
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.