Case Study: Pharmaceutical Hazardous Chemical PHA Case Study
Industry: Pharmaceutical Manufacturing
Purpose of the Case Study
This case study describes recurring PHA renewals conducted for a pharmaceutical company that uses hazardous solvents to apply coatings to pharmaceutical powders for timed-release.
This pharmaceutical company has divided their hazardous processes into five areas, which must be renewed every five years, so a renewal is scheduled for one area every year.
During the PHA renewals, ADF carefully dis-assembles the steps of this process and analyzes the hazards to identify the necessary measures to ensure safe operation, even during non-routine tasks, such as equipment maintenance and flushing of the piping with water.
Brief Overview of Process Safety Management and PHA
Process Safety Management (PSM) is a systematic, performance‑based management framework designed to prevent catastrophic releases of hazardous chemicals (toxic, flammable, reactive, or explosive). In the U.S., it is defined by OSHA 29 CFR 1910.119 and applies to processes exceeding specific chemical thresholds.
PSM focuses on how hazardous processes are designed, operated, maintained, and changed over time, using administrative, technical, and cultural controls. Core elements include maintaining accurate process safety information, formal operating procedures, training, mechanical integrity, management of change, incident investigation, emergency planning, and regular audits.
Process Hazard Analysis (PHA) is a key element within PSM and refers to a structured, systematic evaluation of process hazards to identify potential accident scenarios, assess risk, and verify that safeguards are adequate.
PHAs are typically conducted using recognized methodologies such as HAZOP, What‑If, Checklist, FMEA, or LOPA, and they examine process nodes, deviations, causes, consequences, and existing protections. The output of a PHA is a set of documented findings and recommendations that drive risk reduction through engineering controls, procedural changes, or additional safeguards.
PHAs must be periodically revalidated to ensure continued effectiveness.
Project Background and Context
The pharmaceutical client conducted their original PHAs, divided into five separate processes, using PHA-Works software, which is not licensed for use outside of the original provider’s clients.
The pharmaceutical company wishes to maintain their PHAs in this original software but prefers ADFs expertise and knowledge of their processes to conduct the required renewals. Therefore, ADF has conducted these renewals using the client’s own computer, which maintains the PHA-Works license.
ADF has gone through two rounds of renewals for all five process areas over the past ten years.
ADF also conducts PSM audits for this facility every five years.
Industry Overview
This pharmaceutical client uses large quantities of hazardous solvents to apply coatings to pharmaceutical powders for timed release. The use of such solvents is common in the pharmaceutical industry. The solvents are recovered from the process and re-circulated via large storage tanks.
The quantities used are sufficient to trigger the requirements for Process Safety Management regulation, including the need for Process Hazard Analyses.
Facility Description
Facility Overview
The client’s site is a pharmaceutical facility in Ohio.
The Company’s Process and Operations
The pharmaceutical company coats pharmaceutical powders and makes tablets and micro tablets for inclusion in capsules.
ADF’s Process Hazard Analysis Methodology
Assessment Techniques
The first step in the process is to determine the hazardous characteristics of the chemicals handled on the site, based on one or more of the following:
- Toxicity
- Flammability
- Reactivity
The next step is to set up the PHA by determining the appropriate areas of risk in the process from current Process Flow Diagrams or P&ID’s, which must accurately show all steps in the process, including start-ups, shutdowns, emergency releases, or maintenance procedures. The actual PHA review meeting may then be held at the site and must include the following participants, at minimum:
A. Qualified PHA Facilitator
B. Site Engineer
C. Experienced Operator and/or Maintenance Personnel
D. Facility or Operations Manager
E. Site Safety Manager
The duration of the on-site PHA review depends upon the overall complexity and size of the facility, the materials handled and the accuracy and completeness of the process documentation. Information to be identified and evaluated at the PHA includes:
A. Review of hazardous chemicals handled
B. Identification of all potential areas of risk and likelihood in each process node
C. Safe operating ranges
D. Explosion, fire, or release prevention and protection methods
F. Propagation paths and potential for exposure
G. Recommendations for additional protection measures
Finally, the PHA Facilitator will summarize the identified hazards, and agreed upon implementation plan and schedule to address all risks to an acceptable level.
Furthermore, all future changes to the processes or chemicals handled must be documented through a Management of Change procedure to determine necessary safety system changes and kept with the official PSM documentation by the facility safety coordinator.
Data Collection
Generally, the Safety Data Sheets provide comprehensive information on hazardous chemicals. If this data is unavailable, a qualified lab will need to be contacted.
Risk Identification
ADF utilizes PHA-Pro software for Process Hazard Analyses and has experience with PHA-Works software if desired.
Project Findings and Analysis
Hazard Identification
The hazardous chemicals used at this facility include cyclohexane and acetone.
Risk Assessment
ADF utilizes PHA-Works software for this facility but uses PHA-Pro software elsewhere.
Safety Systems Evaluation
The existing process nodes and procedures were identified in advance of the PHAs, which have each been renewed twice.
ADF’s Post Analysis Recommendations
Preventive Measures
The PHA renewals have been expanded due to an event in 2024 that occurred during a system water flush. The water pushed solvent through the piping to a roof-mounted thermal oxidizer, resulting in an explosion.
A larger drain and valving were added to the process, as well as explosion isolation gates upstream of the thermal oxidizer.
Emergency Response Planning
The site maintains emergency response plans for this chemical with the local fire department.
Employee Training and Awareness
The site maintains emergency response plans for this chemical with the local fire department.
PHA Implementation—Our Project Management Approach
ADF’s Project Planning and Execution
ADF designed the process upgrades following the 2024 incident.
Timeline and milestones
The thermal oxidizer was repaired, and new ductwork was installed to get the plant running. A new thermal oxidizer has been purchased and will start up in mid-2026.
Innovative Solutions and Technologies
ADF was able to confirm the safety of the temporary oxidizer operation and has re-designed the ductwork to allow installation of a new system in a different location.
Continuous Improvement
The PHA must be re-validated every five years or whenever a process change is made.
Project Conclusion
Summary of Key Findings
The system drain was too small to prevent flush water from rising into the ductwork. A new design prevents water from reaching the vent ducts and a new oxidizer will start up in 2026.
Summary of PHA Implementation
ADF was involved in the Incident Investigation process and has designed both temporary and permanent solutions.
Contact and Engagement Information
Contact Details:
Matt Williamson, P.E.
Director of Engineering
(937) 510-7375
mwilliamson@adfengineering.com
