The key is to use a systematic, science-based approach to identify potential hazards at each layer and implement appropriate preventive controls. The controls should be validated, monitored, verified and documented as part of the overall contamination control strategy (system). Regular review and updates are needed to ensure the controls remain effective.
Layers of Controls Analysis (LOCA) provides a comprehensive framework for evaluating multiple layers of protection to reduce and manage operational risks. By examining both preventive and mitigative control measures simultaneously, LOCA allows organizations to gain a holistic view of their risk management strategy. This approach is particularly valuable in complex operational environments where multiple safeguards and protective systems are in place.
One of the key strengths of LOCA is its ability to identify gaps in protection. By systematically analyzing each layer of control, from basic process design to emergency response procedures, LOCA can reveal areas where additional safeguards may be necessary. This insight is crucial for guiding decisions on implementing new risk reduction measures or enhancing existing ones. The analysis helps organizations prioritize their risk management efforts and allocate resources more effectively.
Furthermore, LOCA provides a structured way to document and justify risk reduction measures. This documentation is invaluable for regulatory compliance, internal audits, and continuous improvement initiatives. By clearly outlining the rationale behind each protective layer and its contribution to overall risk reduction, organizations can demonstrate due diligence in their safety and risk management practices.
Another significant advantage of LOCA is its promotion of a holistic view of risk control. Rather than evaluating individual safeguards in isolation, LOCA considers the cumulative effect of multiple protective layers. This approach recognizes that risk reduction is often achieved through the interaction of various control measures, ranging from engineered systems to administrative procedures and emergency response capabilities.
By building on other risk assessment techniques, such as Hazard and Operability (HAZOP) studies and Fault Tree Analysis, LOCA provides a more complete picture of protection systems. It allows organizations to assess the effectiveness of their entire risk management strategy, from prevention to mitigation, and ensures that risks are reduced to an acceptable level. This comprehensive approach is particularly valuable in high-hazard industries where the consequences of failures can be severe.
LOCA combines elements of two other methods – Layers of Protection Analysis (LOPA) and Layers of Mitigation Analysis (LOMA).
Layers of Protection Analysis
To execute a Layers of Protection Analysis (LOPA), follow these key steps:
Define the hazardous scenario and consequences:
Clearly identify the hazardous event being analyzed
Determine the potential consequences if all protection layers fail
Identify initiating events:
List events that could trigger the hazardous scenario
Estimate the frequency of each initiating event
Identify Independent Protection Layers (IPLs):
Determine existing safeguards that can prevent the scenario
Evaluate if each safeguard qualifies as an IPL (independent, auditable, effective)
Estimate the Probability of Failure on Demand (PFD) for each IPL
Identify Conditional Modifiers:
Determine factors that impact scenario probability (e.g. occupancy, ignition probability)
Estimate probability for each modifier
Calculate scenario frequency:
Multiply initiating event frequency by PFDs of IPLs and conditional modifiers
Compare to risk tolerance criteria:
Determine if calculated frequency meets acceptable risk level
If not, identify need for additional IPLs
Document results:
Record all assumptions, data sources, and calculations
Summarize findings and recommendations
Review and validate:
Have results reviewed by subject matter experts
Validate key assumptions and data inputs
Key aspects for successful LOPA execution
Use a multidisciplinary team
Ensure independence between IPLs
Be conservative in estimates
Focus on prevention rather than mitigation
Consider human factors in IPL reliability
Use consistent data sources and methods
Layers of Mitigation Analysis
LOMA focuses on analyzing reactionary or mitigative measures, as opposed to preventive measures.
A LOCA as part of Contamination Control
A Layers of Controls Analysis (LOCA) can be effectively applied to contamination control in biotech manufacturing by systematically evaluating multiple layers of protection against contamination risks.
To determine potential hazards when conducting a Layer of Controls Analysis (LOCA) for contamination control in biotech, follow these steps:
Form a multidisciplinary team: Include members from manufacturing, quality control, microbiology, engineering, and environmental health & safety to gain diverse perspectives.
Review existing processes and procedures: Examine standard operating procedures, experimental protocols, and equipment manuals to identify potential risks associated with each step.
Consider different hazard types. Focus on categories like:
Chemical hazards (e.g., toxic substances, flammable materials)
Physical hazards (e.g., equipment-related risks)
Radiological hazards (if applicable)
Analyze specific contamination hazard types for biotech settings:
Mix-up: Materials used for the wrong product
Mechanical transfer: Cross-contamination via personnel, supplies, or equipment
Airborne transfer: Contaminant movement through air/HVAC systems
Retention: Inadequate removal of materials from surfaces
Proliferation: Potential growth of biological agents
Conduct a process analysis: Break down each laboratory activity into steps and identify potential hazards at each stage.
Consider human factors: Evaluate potential for human error, such as incorrect handling of materials or improper use of equipment.
Assess facility and equipment: Examine the layout, containment measures, and equipment condition for potential hazards.
Review past incidents and near-misses: Analyze previous safety incidents or close calls to identify recurring or potential hazards.
Consult relevant guidelines and regulations: Reference industry standards, biosafety guidelines, and regulatory requirements to ensure comprehensive hazard identification.
Use brainstorming techniques: Encourage team members to think creatively about potential hazards that may not be immediately obvious.
Evaluate hazards at different scales: Consider how hazards might change as processes scale up from research to production levels.
Facility Design and Engineering Controls
Cleanroom design and classification
HVAC systems with HEPA filtration
Airlocks and pressure cascades
Segregated manufacturing areas
Equipment and Process Design
Closed processing systems
Single-use technologies
Sterilization and sanitization systems
In-line filtration
Operational Controls
Aseptic techniques and procedures
Environmental monitoring programs
Cleaning and disinfection protocols
Personnel gowning and hygiene practices
Quality Control Measures
In-process testing (e.g., bioburden, endotoxin)
Final product sterility testing
Environmental monitoring data review
Batch record review
Organizational Controls
Training programs
Standard operating procedures (SOPs)
Quality management systems
Change control processes
Evaluate reliability and capability of each control:
Review historical performance data for each control measure
Assess the control’s ability to prevent or detect contamination
Consider the control’s consistency in different operating conditions
Consider potential failure modes:
Conduct a Failure Mode and Effects Analysis (FMEA) for each control
Identify potential ways the control could fail or be compromised
Assess the likelihood and impact of each failure mode
Rationale: An important element of the protection of patient safety, our highest priority, is preventing contamination and maintaining sterility, as applicable, for products or clinical materials. We have the important responsibility to assure controls are in place to prevent exposure to unintended and potentially harmful materials by patients being treated with products or participating in clinical trials. Equally important is the protection of personnel working with materials from exposure levels that could exceed safe limits.
Policy objective: To define the expectations in implementing containment controls designed to minimize the likelihood of contamination and if applicable to assure the maintenance of sterility.
Procedures will be implemented to assure:
Establishment of effective means to contain ingredients, in process and finished materials to the manufacturing equipment and containers designed for their use, and which prevent airborne or physical transmittal of foreign materials into ingredients, in process, or finished products or product contact surfaces.
Application of risk based control mechanisms to establish steps to be taken to control cross contamination. Factors to be considered include, but may not be limited to, toxic risk of materials; physical properties that present contamination risk; product contact surfaces; use of lubricants; establishment and monitoring of air pressure differential cascades in manufacturing areas; filtration of air, water, steam, gases, and vacuum; the proper use of cleaning materials, sanitizers, and application of pesticides; and the use of personal protective equipment for employees who work with high risk materials.
Classification of processing areas utilizing accepted international norms for viable and non-viable particulate levels
Design of facilities and utilities to ensure appropriate contamination controls and if applicable aseptic conditions
Definition of standards for and types of personal protective equipment (PPE) and procedures for donning PPE, plus additional personnel controls (such as hand washing and sanitization), and the exclusion of inappropriate materials (such as fiber shedding paper) as conditions of entry into classified areas.
Establishment of alert and action levels of viable and nonviable particulate matter in air, water, gases, product contact surfaces and personnel, together with monitoring methods and frequency, and steps to be taken when such levels are exceeded.
Assessment and validation of the effectiveness of containment controls, through methods such as periodic visualization of airflow patterns; water fills; media fills; and oversight of employee practices
Paul Gustafson, chair of the Pharmaceutical Inspection Co-operation Scheme (PIC/S) and a senior corporate regulatory compliance and enforcement advisor with Health Canada, stated that the plan was to issue the widely anticipated Annex 1 in mid-year 2022. He repeatedly said July to September so that is interesting news and start getting your contamination control strategies going. There will be a one-year period before in force, with 2 years on some of the lyophilizer requirements.
For those keeping track, it retains the provision calling for testing filters used in the sterilization process, pre-use, post-sterilization integrity testing (PUPSIT). The PUPSIT provision “has driven a substantial amount of discussion and has resulted in a number of papers being drafted,” said Gustafson. This was a very gracious understatement, and I have to admit I really admired his Canadian humor.
FDA continues to evaluate COVID inspection measures
Alonza Cruse, Director of the Office of Pharmaceutical Quality Operations at FDA/ORA did a thorough job going through the COVID measures of Remote Regulatory Assessments and Remote Interactive Evaluations and discussed how the agency was in the process of learning how best to do things going forward.
He also clearly state how they were continuing to get back to normal inspections and discussed new personnel in foreign offices, such as India.
Highlights from Panels
One of my favorite panels was Jo Ann Jacobs and Kara Vogt speaking on “Building Resiliency into Single-Use-Technology Systems” They laid out some good work they are doing as part of a startup to design good functional equivalency and supplier management, obviously learning from PPAP and similar measures. Quite well done. While it leans heavily into my own practice around functional equivalency it was good to see such a rock-solid implementation, and I felt like I learned a few good ideas.
I spoke on Contamination Control, Risk Management and the Quality Management System, having a blast doing so. I was followed by Christa Myers who spoke on “Contamination Control Strategy: From Annex 1 Draft Requirements to Implementation in Practice.” We made a good duo and between the two I hope participants got a real solid idea on how to do this contamination control strategy effectively.
Environmental contamination results from the ingress of contaminants from the surrounding production areas or even from outside environments
Cross-contamination is defined as contamination of a starting material, intermediate product or finished product with another starting material or product during production.
Whether performing risk assessments or impact assessments there are six factors to consider in order to determine environmental impact and to inform contamination control.
Amenability of equipment and surfaces to cleaning and sanitization
Personnel presence and flow
Material flow
Proximity to open product or exposed direct product-contact material
Interventions/operations by personnel and their complexity