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Safe and sterile: The challenge of developing a custom guarding solution for a sterile environment

Several years ago, CIBA Vision Sterile Manufacturing was faced with a challenge. The Mississauga, Ont.-based manufacturer of contact lens care products required a custom machine guarding solution for its manufacturing environment — an environment that must be sterile to meet stringent regulatory requirements.

During a routine internal safety audit of the company’s manufacturing environment in 2010, the health and safety committee’s machine guarding team identified the need for more protective guarding for two of the plant’s production lines consisting of two machines. One of these machines sorts the empty bottles and stands them up, and the other machine fills, plugs and caps each bottle. A risk assessment flagged a few pinch points and other moving machine parts that could potentially injure a worker.

CIBA needed a way to separate operator from machine for two reasons: to eliminate the risk of injury, and to further reduce the likelihood of compromising the product since human intervention is the number one source of contamination. The solution would need to have a modular design and be well planned for mechanical and electrical installation.

Creating a solution of this magnitude involves several steps: design, fabrication, implementation and project management, not to mention ensuring compliance with safety laws which, in Ontario, are among the most strictly enforced in the world. Vickers-Warnick was awarded the project because it could fulfill all of these functions. Also, having worked with the company as a supplier of high-tech automation products and services through their distribution division, CIBA trusted that it could provide a turnkey solution with mechanical and electrical engineering and machine guarding expertise.

The process

The engineers faced a challenge that is unique to the pharmaceutical and food and beverage sector: making the machine both safe and sterile — two requirements that can sometimes conflict.

“You want full access to clean the equipment, so ideally it would be open; but for safety reasons, to protect the worker, you need it enclosed,” explains David Jones, director of sales and safety projects, Vickers-Warnick Ltd.

The guarding had to comply with the CSA Z432-04 standard Safeguarding of Machinery. It must not impede the operators’ work or slow down production. Nor could any piece of it hinder in any way the airflow of the room’s HEPA filters in the ceiling, which, in this cleanroom environment, must generate greater than 240 air changes per hour.

Vickers-Warnick proposed a complete design package: “A category 3 stop and interlock circuit to achieve CSA standard and code compliance, while maintaining machine functionality and flexibility.” To achieve compliance, this standalone interlock control system would interface with the existing line control.

Time was a factor. The custom guarding solution would have to be implemented during production shutdown, which gave the company 10 days. That’s 10 days for final fabrication, installation, wiring, programming, troubleshooting, commission and startup, and operator training on the new safety interlock system.

“The Vickers-Warnick team was asked to work on a second shift to avoid conflicts with other shutdown activities,” says Li Feng, CIBA Vision’s chief design engineer.

Collaborating with a CIBA project team right from the start, Vickers-Warnick conducted a risk assessment to precisely identify the plant’s machine safety and guarding needs. Meanwhile, CIBA hired a Pre-Start Health and Safety Review (PSR) engineer at the start of the project. Vickers-Warnick worked with the PSR engineer to confirm requirements, risks and vulnerabilities identified during previous risk assessments, and designed a comprehensive solution that could be implemented within the tight timeframe.

Normally, to custom-build a guarding solution, engineers would work right on the shop floor where the operation actually takes place. But the Vickers-Warnick team didn’t have access to this cleanroom environment and had to find another way. They had to build in flexibility that would allow them to make any necessary changes on the spot during installation.

“The good thing was they worked closely with our operators to find out how they work. They even built a 2×2 wooden mockup and brought it in for the whole team to see it,” Feng says.

Indeed, after the drawings were approved, engineers created a mockup for testing in order to ensure the proposed solution would meet all of the plant’s criteria. Operators were able to test it themselves and, with their confirmation, Vickers-Warnick built and implemented the solution. As managers of the entire project, Vickers-Warnick collaborated with the CIBA HSE team, engineering group, production team and maintenance personnel to make sure the needs of all stakeholders were considered and satisfied.

Safe, clean and sound

The new solution provides adequate separation and machine guarding on CIBA’s equipment, meeting both the safety requirement and hygienic considerations. And it has had zero negative impact on productivity — a fortunate result of involving operators in the design and consultations from day one.

“We at Vickers-Warnick come from an automation background, so we don’t see a successful machine unless it is both safe and productive,” Jones says.

Also, having a custom-built solution means it addresses several needs that are specific to CIBA Vision:  
•     It maximizes operator safety without hindering productivity or access to the machines;
•     It does not let any part of the guarding impact airflow;
•     The materials used are mostly 304L grade stainless steel and Lexan to minimize the likelihood of rust;
•     Every element of the machine, including the guard, is easily accessible for cleaning, maintenance and changeovers; the Lexan panels located at the top of the perimeter are easily removable to allow access to the HEPA filters located in the ceiling; and
•     Finally, hygienic considerations for this aseptic operation comply with FDA guidelines for Sterile Drug Products Produced by Aseptic Processing, under cGMP and Health Canada GMP guidelines.

Operators started using the new system in the fall of 2012.

“The end result was an impressive machine guarding solution that satisfied all requirements,” says Feng, adding that the guard looks as though it originally came with the machines.

Feng believes that teamwork was key to the project’s success.

“Because [Vickers-Warnick] did their due diligence and got buy-in from the operators, everyone was satisfied in the end.”

Michelle Morra-Carlisle is a freelance journalist and corporate writer based in Toronto.