As another year draws to a close, it’s time to take a look back at the articles and topics that have been of the most interest to the readers of Controlled Environments throughout 2017.

The most popular article of the year was “HVAC Design for Cleanrooms,” which discussed how the HVAC system is the “heart” of a facility. There are distinct differences between conventional and cleanroom HVAC setups, as well as between an HVAC system and an HVAC unit. The information in this article is intended to “[simplify] the cleanroom HVAC concept to facilitate conversations with your cleanroom supplier for your next project.”

Alarms are needed in cleanrooms to monitor equipment and product, and can prevent lost revenue and product. “Setting Appropriate Alarm Limits in Sterile Manufacturing Processes” cautions against the misinterpretation of cGMP guidelines as well as uninformed use of environmental monitoring systems, which can doom a cleanroom’s mission before it even begins.

The pharmaceutical industry can sometimes be slow to change. Current cleaning agents may be preferable to older methods, and may overcome the weaknesses that cleanroom facility managers faced in the past. “Changing the Paradigm of Cleaning and Disinfection of Cleanrooms” talks about how to obtain the greatest assurance of contamination control … while noting that the most effective method remains preventing the contamination in the first place.

Ultrasonic cleaning is used in a wide range of professions. Correct cleaning solution formulations, in addition to applicable pre- and post-cleaning procedures, are a vital part of compliance with QC and QA standards. “Guidelines for Ultrasonic Cleaning Solution Selection” helps cleanroom professionals understand the basics: the specific types of contamination that need to be removed, the product composition, post-cleaning steps, and the very definition of the word “clean.”

The Cleanroom Tips section of Controlled Environments features “do’s and don’ts” sent in by our readers. Our most popular tip of 2017 was “Minimizing Human Contamination,” contributed by Michael Rodd of M+W Products, which explained that human contamination is the foremost concern when dealing with cleanrooms.

As cleanrooms come in all shapes and sizes, there’s no one-size-fits-all answer for determining their classification levels. “Understanding What Cleanroom Classifications Mean” discusses how best to tailor your practices, apparel, products, and equipment to meet specific needs. For this article we spoke to Patrick McGee, Cleanroom Division Manager at PortaFab Corp., for details about how to properly accommodate different levels of cleanroom classifications.

Cleanroom facility managers often want to know about best practices in regards to the frequency of particulate and viable aseptic monitoring. Recommendations are provided by WHO and USP <1116>. Monitoring frequency should be made in accordance with the manufacturer’s risk assessment. “Microbial Air Sampling in Pharmaceutical Aseptic Monitoring” discusses this issue in depth.

Our “Regulatory Forum” columnist, Bikash Chatterjee, wrote “Understanding Annex 16 Changes for Qualified Persons and Batch Release,” which detailed recent changes in the European Union concerning responsibilities related to drug quality.

There are many different types of cleanrooms, built around all sorts of needs. “The Costs of Building a Cleanroom” described various kinds of facilities, as well as what must be considered when designing and constructing them, as well as the hidden costs.

Rounding out our top 10 articles of the year was our annual Cleanroom Trends and Salary Survey, where we sent a questionnaire to our readers to analyze cleanroom facility-related purchasing decisions, as well as their salary and benefits packages and job satisfaction. We used these results to analyze the latest trends — check out the article to compare your cleanroom and overall compensation package with those of your peers, and to see what could be in store for the cleanroom industry in the future.

Controlled Environments will continue to track these topics, as well as others related to cleanrooms and contamination control, as we bring you fresh new content in 2018. Thanks for reading!