Contamination Control Strategies: what they are and why you need them

28 June 2021

Contamination Control Strategies are mentioned throughout regulation and guidance documents. The recent draft of Annex 1 mentions contamination control strategies numerous times, stating that these should be in place across all sterile manufacturing sites to “define all critical control points and assess the effectiveness of all the controls and monitoring measures to manage risks associated with contamination”. This means that the strategy should assess and manage all risks to the sterile manufacturing environment using a risk-based approach.

But what is a contamination control strategy?

It is a formally documented strategy with multiple elements implemented site-wide, to collate all of the precautions a site should have in place to ensure control of their manufacturing environment. The strategy should allow for the assessment of procedures implemented. Any strategy implemented should be justified through an analysis of the risk.

According to Annex 1, these strategies should be updated continuously, driving improvement to both the manufacturing and control processes. Therefore, assessment of the environment and the contamination control strategies should be performed regularly, performing analysis and trending of environmental monitoring data, utilities and sterilisation processes.

Systems such as SmartControl, which allows the easy and efficient generation of analysis tools such as graphs and context specific reports, allow for these assessments to be performed regularly and simply.

Why are contamination control strategies important?

The release of sterile products relies on, as the name suggests, the finished product being sterile. However, finished product sterility testing or other terminal process tests cannot be relied upon to confirm the sterility of an entire batch – they are a snapshot of samples used to provide an indication of the performance of the product.

It is therefore essential for QPs and regulatory authorities to have assurance of the sterility of the entire process. This is generally provided through a sterility assurance program, which relies on a thorough contamination control strategy to assess their processes.

So what goes into a contamination control strategy?

Annex 1 clearly defines the minimum consideration requirements to be assessed within a contamination control strategy. These requirements are set out in the table below:

Design of processes and plant

Vendor approval

Premises and equipment

Process risk assessment


Process validation


Preventative maintenance

Raw material controls

Quality systems

Product containers and closures

Prevention of contamination and continuous improvements using trending, investigation, CAPA and RCAs as well as the need for more comprehensive investigational tools

Outsourced services

Cleaning and disinfection

Monitoring systems


Contamination control methods should include a series of linked events and measures which are typically assessed and controlled individually; however the effectiveness of these should be considered as a whole. The development and review of a contamination control strategy requires in-depth knowledge of the products and processes with the aim to minimise contamination risk.

All aspects of the process must be considered from the design of the facility to the containers. This includes the equipment available within the facility, including barrier technology (such as RABS or isolators) which should be assessed and monitored to ensure continued compliance.

The contamination control strategy should ensure that personnel are trained to perform processes correctly, and contamination control should be included as part of that training.

They should also document systems to ensure that raw materials and equipment used within the manufacturing process are assessed and utilised correctly, especially where these have been sourced from outside of the company. Therefore, appropriate approval of vendors is essential. Similarly, if services are outsourced, this should be documented within the contamination control strategy and assessment should be made.

Process and equipment validation should be controlled and documented within the strategy before implementation to ensure compliance.

Cleaning and disinfection procedures should be documented, and these should be utilised to prevent contamination rather than to fix a contamination problem; however, they should also be in place in case of breaches. Maintenance should be performed before an issue occurs (preventative maintenance).

All of these factors should be managed through quality risk management principles, assessing the risk to the process and the final product. Quality systems should allow the effectiveness of contamination control strategies to be assessed using trending and investigation, thus hopefully preventing contamination, and leading to continuous improvement using preventative or corrective actions.

The environmental monitoring plan.

One significant part of a contamination control strategy is the environmental monitoring plan. This environmental monitoring plan should provide meaningful data, which should regularly be reviewed to allow the continuous improvement of manufacturing and monitoring processes.

The level of monitoring should be assessed through a risk-based approach, with increased monitoring occurring at the highest risk areas of contamination to the process (e.g. Grade A and B areas should have increased monitoring levels).

All potential sources of contamination should be considered, as well as potential routes of transfer of contamination to production areas. The draft of Annex 1 now has greater expectation around personnel monitoring following critical interventions and exit from Grade B areas. This means a greater emphasis must be placed upon the review of critical data produced from these monitoring plans.

Assessment of environmental monitoring plans must occur regularly as part of the contamination control strategy. Trending reviews allow assessment of data produced and allows setting of appropriate action and alert limits for areas.

Once again, a system such as SmartControl allows easier trending of data. Analysis tools allow for review of all data in easy to understand formats, such as providing contamination rates and limit breach floorplans. This provides manufacturers with a greater understanding of the state of the facility. Problem areas are highlighted with Smart Insights, and trends are automatically detected if they are defined by the user. Context specific reports on operators allow analysis of personnel and location specific reports allow review of critical areas.

The Annex 1 revision makes it clear that manufacturers are expected to thoroughly understand entire processes in enough detail to effectively assess contamination control and help mitigate potential contamination sources.

SmartControl can help to provide this understanding by giving facility overviews and insight into the effectiveness of contamination control.

Get in touch today to find out more about how SmartControl can support your contamination control strategies, and help solve other environmental monitoring challenges you face in your facility.