The importance of effective dust control and containment in the pharmaceutical workplace

Oral solid dosage products (OSD) such as tablets, pills or capsules contains Active Pharmaceutical Ingredients (APIs). These APIs create very fine dusts and often high solvent concentrations during the product handling and manufacturing processes. To protect workers’ health and to avoid cross-contamination of products, effective filtration combined with containment solutions is required.

Understand your process

In many instances, the handling of pharmaceutical ingredients generates harmful dusts during the manufacturing and packaging processes of Oral Solid Dosage (OSD) products. To comply with the industry’s stringent health and safety requirements while meeting mandatory quality requirements, a reliable and efficient capture and extraction solution is required. Before considering a dust extraction solution, it is important to fully understand the application and processed ingredients.

Typical applications: Tablet pressing, tablet coating, fluid bed drying, spray drying, blending, granulation

Handled ingredients: Powders, granular ingredients, active pharmaceutical ingredients (APIs), solvents

A comprehensive risk assessment of each and every application is essential before establishing the requirements for the right extraction solution.

The questions that need answering when analysing the potential risks associated with dusts generated in the workplace include the following:

• Are the dusts potentially harmful to human health and the environment?
• Do they have the potential to cause explosions or fires?
• Do they have the potential to interfere with moving parts of machinery and electrical components?
• Is there the potential for cross-contamination of products?
   

If you are uncertain or don’t have all the relevant data, it’s recommended to evaluate the properties of the processed material. Besides analysing the dust characteristic, it also makes sense to perform a dust hazard analysis to evaluate the risk for employee exposure and a dust explosion & flammability test, which can be required according to ATEX-directives.

Industry’s challenges & concerns

There are three critical areas for consideration and risk assessment when handling pharmaceutical dusts:

Personnel exposure to potent, toxic or allergenic dusts

The more potent the dust, the lower the exposure limits set for personnel coming into contact with the materials. It is the employer’s responsibility to know and understand the exposure limits for each product they are using, and take the necessary steps to ensure the limits are not exceeded.

Cross-contamination of products

Airborne dust can have negative effects on the quality of your products and lead to non-compliance with authorities like the Therapeutic Goods Administration (TGA). Worst-case scenarios are product call-backs and brand damage.

Combustion risk and dust explosions

In pharmaceutical manufacturing, it is common to extract process air containing combustible dusts, flammable gases, mists and vapours, or a mixture of some or all of these. Containing such an explosive atmosphere in a sealed environment (such as a dust collector) with an ignition source and you have all the necessary constituent parts for an explosion to occur.

There is a growing trend for pharmaceutical ingredients, particularly APIs, to consist of smaller molecules to provide faster reactions and greater potency. Solvents are often used in the processing phases. Whilst providing significant benefits in terms of drug delivery and performance, it creates a number of challenges for pharma manufacturers and their production processes:

• The APIs create very fine dusts and often high solvent concentrations during the product handling and manufacturing processes. The finer the dust, the greater explosive potential due to increased surface area and greater concentration.
• The fine dusts also pose the greatest risk to the worker’s health, with harmful particles being retained in the lungs.

Application-specific dust extraction solutions

As there is a wide variety in pharmaceutical manufacturing and packaging processes, a dust extraction system has to be tailored to the customer’s needs to provide the required safety and filtration efficiency. Especially on processes in the pharma industry, dust extraction solutions have to withstand higher Pmax and KSt values on dusts, as well as a greater number of applications involving hybrid dust and gas mixtures. Here’s what you should take into consideration when determining dust extraction for your application:

Capture Solution

It is important to extract the dust directly at the source to ensure that it does not escape into the workplace.

Dust Collector Unit

The dust collector unit is essentially a self-cleaning filter housing with a fan that moves the contaminated air out of the workplace, filters the dust and fume particles, and discharges them into a bin or similar receptacle. The choice of filter material is critical and dependent on the dust characteristics and application conditions.

Filtration Rate

The area of filter material required is also important so that the dust collector is sized appropriately to handle the airflow and dust concentration as effectively and efficiently as possible.

Containment

Another critical consideration, and one which is often overlooked, involves effective containment of potent dusts. Once the airborne dust is captured at source, it needs to be contained at every stage of the extraction process. Containment is also essential during maintenance of the dust collector unit. Especially for potent dusts, there should be a specific and integral safe change operation for both the dust discharge system and the filter cartridge change-out. The so-called Bag-In/Bag-Out (BIBO) technology is used to prevent operator exposure and the collected material from escaping when performing filter change-outs. The continuous liner technology is used at the discharge system to contain the dust released from the cartridges to the hopper during automatic pulse-cleaning of the system.

Explosion Protection

If the dust is considered to be combustible or explosive, there are certain values that need to be determined in order to select the correct and ATEX-certified explosion protection system for each dust collector. The goal of these systems is to control an explosion, to keep employees safe, and minimise plant and equipment damage.

• Passive Systems: These systems utilise passive components such as vent panels and mechanical flat valves. Passive systems are very reliable but also have limitations in their usage.
• Active Systems: Active systems involve much more costly technology but allow a greater flexibility in installation.

Energy Consumption

Today energy consumption has become increasingly important and selecting an energy-efficient solution is vital. In this, the design of the extraction system, the pressure drop of the dust collector and the efficiency of the fan combined with accurate control must be reviewed. If you analyse the cost of operating a system, the energy for the fan comes out as the main cost, so selecting a lower filter load and consequently considerably lower pressure drop is a profitable and a good choice in this age.

Investing in the right air filtration solutions is essential for a healthier workplace and improved operational performance. Contact your local Camfil specialists or visit our website for more information: https://www.camfil.com/en-au/insights/dust-fume-and-mist-extraction/pharmaceutical.