Part One – Compounding Pharmacies: Regulatory Airflow and Filtration

State regulators enact laws that govern many industries, including compounding pharmacies.

Frequently, they rely on performance standards established by other organizations, such as the International Organization for Standardization ( ISO), American National Standards Institute (ANSI), and NSF International (formerly National Sanitation Foundation.).

The acronyms of these organizations are often attached to standards cited in legislation, such as “ISO Class 5.”

Legislation frequently cites established national and international standards, so there can be recurrent regulation overlap from state to state. For instance,California and New Jersey legislation requires many of the same standards as Oklahoma Pharmacy Law. As you read this three-part series of blog entries, it’s likely you’ll find many of the airflow and filtration standards in Oklahoma Pharmacy Law may also apply to other state pharmacy laws.

NOTE: Cabinets, clean rooms, hoods, and isolators have varied functionality and have differing roles in the compounding pharmacy. See your state’s pharmacy laws for guidance on the role these devices play in your practice. Click here for links to the pharmacy boards listed on the National Association of Pharmacy Boards (NAPB) website.

Three-part series. This is the first of three blogs that review specific sections in the state of Oklahoma’s Pharmacy Law Bookand relate them to the performance of Sentry Air Systems product lines.

This entry discusses the generic qualities of airflow within respiratory safety equipment as noted in the Oklahoma Pharmacy Law Book.

The second article covers the equipment specifications in section 535:15-10-14 for compounding non-sterile hazardous drugs and relates them to our line of HEPA-Filtered Powder Containment Hoods.

The third article discusses the equipment specifications for compounding sterile products in Part 3, Good Compounding Practice for Sterile Products.

Some definitions. For compounding pharmacies, our containment hoods may be called primary engineering controls, sometimes referred to as PECs. They may also be referred to as isolators. The category of material being handled – hazardous, sterile, or non-sterile – and nature of the material – liquid, powder, gel, for example — require different types of engineered controls to protect products, people and the work environment. A certified industrial hygienist should be consulted to determine the best configuration of primary and secondary engineering controls for your pharmacy.

Engineered air flow. Air flow can be engineered to do several tasks in a pharmacy. In most cases, air is either designed to move unwanted materials away from a technician and force the capture of those unwanted materials by a filter, OR it is engineered to protect sterile compounding products from contamination (usually done by using HEPA-filtered, positive pressure air).

Air can be engineered to flow smoothly or with turbulence. Typically, a smooth and even flow of air (laminar flow) is recommended for pharmaceutical applications.

An engineered air flow can create changes to air pressure within a room or within a small enclosure. Both negative-pressure and positive-pressure air flow can be used in a pharmaceutical environment for varied tasks.

Many of the specifications in the Oklahoma Pharmacy Law Book address the qualities of engineered air in and around cabinets. See the following table for examples:

Some airflow terms in the law book
minimum average inflow/velocity
speed at which air flows past a specific point in a cabinet; may be expressed as feet per minute (ft/m) or meters per second (m/s)
airflow capacity
rate at which air can flow; may be expressed as a maximum airflow or as airflow controlled to a specific rate
air exchange
replacement of air within an enclosed space with air from outside the enclosure
unidirectional air
airflow in one direction is permissible in a segregated compounding area
filtered air
air that has been cleansed by a filter, such as a HEPA filter
laminar airflow
air in a constant stream; not turbulent
airflow into a cabinet
negative pressure
airflow into and through the cabinet maintains negative pressure within the enclosure.
pressure drop
the impact a filter has on airflow through a cabinet
air that has flowed through a cabinet to the surrounding area
ventilation includes both the flow of air to outside the cabinet as well as to outside the building
particles per cubic feet of air
used to express the efficiency of an air filter; particles are expressed in number and in size in microns after the air has flowed through the filter as in x/ft3

Sentry Air Systems offers a range of containment hoods in widths of 12, 18, 24, 30, 40, 50, 60 and 70 inches.

This 40” ductless power containment hood uses a powerful fan and filtration system to pull harmful airborne powder and particulate away from the pharmacist’s breathing zone and into the HEPA filter.

We also offer positive pressure systems in widths of 12, 18, 24, 30, and 40 inches. 

Our portable clean rooms are used in a variety of applications, including compounding, field testing, stem cell therapy practices and tissue culturing.

Sentry Air Systems provides this information as a customer service. If you have air quality concerns or questions pertaining to specific laws and regulations, contact an industrial hygienist or your state’s pharmacy board.