Chemical Reactive Risk Identify by using Chemical Reactive Worksheet (CRW4) Software

Chemical Reactive Risk Identify by using Chemical Reactive Worksheet (CRW4) Software

Mr. Dinesh H. Gore

Student – Department of Chemical Engineering, School of Engineering and Applied Sciences, University of Mumbai (Kalyan Sub Centre), Maharashtra, India.

Dr. Satyajit M. Deshmukh

Professor – Department of Chemical Engineering, School of Engineering and Applied Sciences, University of Mumbai (Kalyan Sub Centre), Maharashtra, India.

Abstract: Chemical reactive hazard identifications are important components in specialty chemicals, agrochemicals, pharmaceuticals, petrochemicals industries for avoid the process safety incidents. Industries that work with volatile, explosive or hazardous materials, it is vital to ensure that the safest practices are being followed to reduce the chances of fires and damage to products, facilities or injuries to staff. Chemical reactive hazard study was caried out literature study of explosive materials and process at early phase of molecules development. In chemical reactive hazard identification stage, preliminary identify and understand potential hazards, chemical process and reaction hazards, health hazards, explosion hazards and dust hazards, and combustible gas and vapor flammability, environmental hazards and past incidents data through the systematize the literature review and investigated scientific papers as well as professional articles and so-called grey literature.

In this paper, identify the few past chemical reactive hazards incident root cause through the Chemical Reactive Worksheet (CRW4) software. This software free and easily available on CCPS website portal. Chemical reactive worksheet was carried out through literature survey, Brethericks handbook data, molecular structure/high energetic functional group consideration, chemical incompatibility, previous accident history, CRW4 software helps business in process industries to understand and then reduce the risks in their production lifecycle and eliminate or control risks in their facilities and comply with the highest standards of safety.

Keywords – Process safety, Chemical Reactive Hazard, Chemical reactive worksheet etc.

1. INTRODUCTION:

   Chemical reactive hazards arise when substances undergo unintended or uncontrolled reactions that release heat, gas, pressure, or hazardous by-products, potentially leading to thermal runaway, explosions, fires, or toxic releases. Understanding these hazards is essential in chemical manufacturing, storage, and handling, and one widely used tool for early-stage hazard screening is CRW4 (Chemical Reactivity Worksheet 4). CRW4 is a chemical incompatibility assessment software developed to help users identify potential reactivity risks by comparing chemicals against a comprehensive database of reactive groups and documented incompatibilities. The core feature of CRW4 is its compatibility matrix, which evaluates two or more chemicals or reactive groups and indicates whether combinations are benign, exothermic, gas-evolving, or potentially violent, thus helping users recognize where additional hazard studies or engineering controls are required. CRW4 provides a foundational understanding of incompatibility- driven hazards and enhances decision-making in HAZOP, MOC, and general process-safety management by alerting engineers and operators to conditions where chemical reactivity may pose significant danger.

2. Chemical Reactive Hazards:

   Reactivity refers to the propensity of a substance or a mixture of substances to experience a chemical transformation when subjected to appropriate conditions. Recognize and manage reactivity risks within two main classifications – reactive substances and reactive interactions.

   1. Reactive Substances – Reactive materials are typically defined as substances that can pose hazards on their own when they undergo reactions triggered by heat, pressure, shock, friction, a catalyst, or exposure to air or water.

   2. Reactive Interactions – Reactive interactions involve the combination of two or more substances, which can create a potentially dangerous chemical situation.

   1. Chemical reactive incident

      Numerous facilities handle chemically reactive materials and systems without fully understanding the associated hazards. Some are cognizant of these risks but lack sufficient protective measures. Additionally, there are instances where individual materials are managed properly, yet the risk of a significant incident arises if these materials are accidentally mixed.

      1. Swimming Pool Chemical Plant Fire Springfield, Massachusetts (June 17, 1988)

         Rainwater leaked into storage area containing numerous drums of dry swimming pool chemicals, leading to an explosion. This explosion, along with the subsequent fire, activated the sprinkler system, which drenched the remaining drums. The fire, explosions, and chlorine emissions persisted for three days. More than 6000 peoples were evacuated, and 275 people were treated in hospitals for skin burns and respiratory issues.[1]

         In this incident, leakage rainwater contact with trichloro-S-triazinctrione (TCT) compound and produce the heat. In presence of heat, TCT compound breakdown and formed large amount of Chlorine gas and by product is nitrogen chloride. By using CRW software, identify the all compounds are incompatible with each other and shows exothermic reaction with gases produces.

         Figure 1 Chemical Compatibility chart of Fire incident, Massachusetts (June 17, 1988)

         Sr. No.	Chemical Name	Pair with another chemical	Hazard Summary	Potential Gases
         1	Trichloro-S- triazinctrione (TCT)	Water		Acid Fumes Carbon Dioxide Chlorine Chlorine Dioxid
         		Air		No gas generation predicted

         1. Reaction products may be corrosive

         2. Reaction liberates gaseous products and may cause pressurization

         3. Exothermic reaction at ambient temperatures (releases heat)

         4. Reaction may be particularly intense, violent, or explosive

         5. Reaction products may be toxic

         1. Reaction products may be flammable.

         2. Exothermic reaction at ambient temperatures (releases heat)

         3. Reaction may be particularly intense, violent, or explosive

         		Chlorine, Nitrogen Chloride		Acid Fumes Carbon Dioxide Chlorine Chlorine Dioxid
         		Soda Ash	1 Reaction liberates gaseous products and may cause pressurization 2. Exothermic reaction at ambient temperatures (releases heat)	Acid Fumes Carbon Dioxide Hydrogen Halide
         2	Soda ash	Water	Reaction liberates gaseous products and may cause pressurization	No gas generation predicted
         		Air	No known hazardous reaction	No gas geneation predicted
         		Chlorine, Nitrogen Chloride		Carbon Dioxide

         1. Reaction products may be corrosive, explosive or sensitive to shock or friction, flammable, toxic

         2. Reaction liberates gaseous products and may cause pressurization

         3. Exothermic reaction at ambient temperatures (releases heat)

         4. Reaction may be particularly intense, violent, or explosive

         1. Reaction liberates gaseous products and may cause pressurization

         2. Exothermic reaction at ambient temperatures (releases heat)

         Table 1 Chemical reactive hazard prediction of TCT & soda ash compound by using CRW4 software

         In above table captured chemical reactive hazard prediction, hazard summary and potential gas generation data of TCT, Soda ash, Chlorine gas, Nitrogen chloride, Water and Air all chemical shows reactive incompatible behaviors with each other.

      2. Napp Technologies facility at Lodi, New Jersey on April 21, 1995

         On April 21, 1995, an explosion and subsequent fire occurred at the Napp Technologies facility in Lodi, New Jersey. This incident led to fatalities, injuries, the evacuation of nearby residents, and significant damage both on the premises and in the surrounding area. The incident involved a commercial chemical formulation known as ACR 9031 GPA, a gold precipitating agent owned by Technic Inc. based in Cranston, Rhode Island. This mixture consists of sodium hydrosulfite, aluminum powder, potassium carbonate, and benzaldehyde, collectively referred to as GPA.

         Five employees lost their lives due to an explosion of a blender. This equipment was utilized for mixing various dry powders, such as aluminum powder and sodium hydrosulfite. The probable reason for the explosion was the accidental entry of water into the blender, potentially resulting from a malfunctioning water-cooled seal. [2]

         Figure 2 – Chemical Compatibility chart of Napp Technologies facility at Lodi, New Jersey on April 21, 1995

         Sr. No.	Chemical Name	Pair with another chemical	Hazard Summary	Potential Gases
         1	Water	Sodium hydrosulfite | Sodium dithionite		No gas generation predicted
         		Aluminum Powder		Hydrogen
         		Potassium Carbonate		Carbon Dioxide
         		Soda Ash	1 Reaction liberates gaseous products and may cause pressurization 2. Exothermic reaction at ambient temperatures (releases heat)	Acid Fumes Carbon Dioxide Hydrogen Halide
         		Benzaldehyde, Air	No known hazardous reaction	No gas generation predicted
         2	Aluminum Powder	Sodium hydrosulfite | Sodium dithionite		Hydrogen
         		Potassium Carbonate		No gas generation predicted
         		Benzaldehyde		Hydrogen
         		Air	1 Reaction liberates gaseous products and may cause pressurization	Carbon Dioxide Nitrogen Oxides Sulfur Dioxide
         3.	Benzaldehyde	Sodium hydrosulfite | Sodium dithionite		No gas generation predicted
         		Potassium Carbonate	Exothermic reaction at ambient temperatures (releases heat)	No gas generation predicted

         1. Reaction products may be explosive or sensitive to shock or friction

         2. Exothermic reaction at ambient temperatures (releases heat)

         3. Reaction may be particularly intense, violent, or explosive

         1. Reaction products may be flammable, toxic

         2. Reaction liberates gaseous products and may cause pressurization

         3. Exothermic reaction at ambient temperatures (releases heat)

         1. Reaction liberates gaseous products and may cause pressurization

         1. Reaction products may be explosive or sensitive to shock or friction

         2. Exothermic reaction at ambient temperatures (releases heat)

         3. Reaction may be particularly intense, violent, or explosive

         1. Exothermic reaction at ambient temperatures (releases heat)

         2. Reaction may be particularly intense, violent, or explosive

         1. Reaction products may be flammable

         2. Exothermic reaction at ambient temperatures (releases heat)

         3. Polymerization reaction may become intense and may cause pressurization

         1. Exothermic reaction at ambient temperatures (releases heat)

         2. Reaction may be particularly intense, violent, or explosive

         1. Exothermic reaction at ambient temperatures (releases heat)

         2. Reaction may be particularly intense, violent, or explosive

         Table 2 Chemical reactive hazard prediction of Sodium hydrosulfite, Potassium carbonate, Aluminum Powder, Benzaldehyde compound by using CRW4 software

         In above table captured chemical reactive hazard prediction, hazard summary and potential gas generation data of Sodium hydrosulfite, Potassium carbonate, Aluminum Powder, Benzaldehyde Water and Air all chemical shows reactive incompatible behaviors with each other.

         Based on the chemical reactive hazard, water is incompatible, highly reactive with the sodium hydrosulfite, Aluminum powder and potassium carbonate and potential to produce hydrogen flammable gas.

3. EVALUATING CHEMICAL REACTIVE RISK ASSESSMENT

   When designing a new operation process or facility, when implementing changes or introducing new materials in the existing operations process. It is essential to be aware of the answers to the following four questions when managing both new and existing substances in the process.

   Do We Handle Reactive Materials? Can we have Reactive Interactions?

   What Data Do We Need to Control These Hazards?

   What Safeguards Do We Need to Control These Hazards?

   1. Manage Reactive Materials –

      To determine whether we manage reactive materials, it is essential to identify substances that may lead to hazardous releases, including heat, explosive energy, or toxic vapors and gases that could compromise a container's integrity under conditions that might reasonably arise in both normal and abnormal scenarios. This process is often referred to as an intrinsic evaluation, as it focuses on the inherent properties of the materials in question.

      Material Safety Data Sheets (MSDS) serve as an excellent starting point for identifying reactive substances. In MSDS, a section labeled Reactivity Data, Stability and Reactivity, or something similar that details the primary reactivity risks associated with the material. While this information may not cover all aspects you need to be aware of, it will provide an immediate alert regarding significant reactivity hazards linked to the substance. Additional insights can often be fund in sections related to firefighting measures or explosion data.

   2. Manage Reactive Interactions

      Many substances that are not classified as "reactive materials" can still pose significant risks when they come into contact with other incompatible substances. These other materials may be present intentionally, such as when the correct substance is added in an incorrect quantity, or unintentionally, as in the case of contaminants like rust or lubricants. Additionally, the conditions under which these materials are utilizedsuch as pressure, temperature, humidity, and concentrationcan significantly alter their reactive properties. Consequently, recognizing reactivity hazards that arise from the combination of two or more materials is highly context- specific and cannot be effectively managed through a simple checklist or rule-based approach. This section introduces an external methodology for identifying reactive interactions that extends beyond the inherent characteristics of the individual materials relevant to your operations.

      it is essential to assess the materials present on-site and identify which of these materials may react with one another. There are several user-friendly tools available to assist in this evaluation, with one of the most effective being a compatibility chart. This tool may also be referred to as a chemical compatibility chart, a chemical interactivity chart, or a chemical interaction matrix in various references.

   3. Control the Reactive Hazards

      The required information for each reactive material will likely vary based on the characteristics of the material and the methods of storage and usage.

      • Materials of construction to use and to avoid

      • Common materials and contaminants to avoid (e.g., air, water, rust, oil, acids, caustic)

      • Storage configurations, maximum quantities, and minimum/maximum storage temperatures

      • Shelf-life considerations

      • What to do in the event of a leak or spill

      • What to do if an unwanted reaction starts

      • How to fight a fire involving the material

      • Possible toxic/corrosive/flammable products of reaction or decomposition

      • Any special considerations (light-sensitive substance, forms unstable byproducts over time)

      If materials not available reactive interactions data. It is essential to first determine the amount of heat or gas that could be produced. In certain instances, this can be straightforward by consulting the heat of mixing data found in a technical reference book. However, in more complex cases, specialized equipment (ARC, ARSST, DSC) may be necessary to precisely measure the heat and pressure generated during a chemical reaction.

   4. Safeguards to Control the Reactive Hazard

      In situations where reactivity hazards cannot be eliminated, it is essential to implement multiple layers of safeguards as protective measures. These safeguards are crucial in preventing abnormal conditions, mitigating the risk of incidents like fires and explosions, and lessening the impact of any occurrences that may arise. For these safeguards to be effective, they must be meticulously designed, correctly installed, and consistently maintained in operational condition throughout the duration of your facility's operation.

      • Ensure that all staff are trained to recognize reactivity hazards and incompatibilities, as well as to understand the maximum allowable storage temperatures and quantities.

      • Design storage and handling equipment with all compatible materials of construction

      • Avoid heating coils, space heaters, and all other heat sources for thermally sensitive materials

      • Avoid confinement when possible; otherwise, provide adequate emergency relief protection

      • Avoid the possibility of pumping a liquid reactive material against a closed or plugged line

      • Locate storage areas away from operating areas in secured and monitored locations

      • Monitor material and building temperatures where feasible with high temperature alarms

      • Clearly label and identify all reactive materials, and what must be avoided (e.g., heat, water)

      • Positively segregate and separate incompatible materials using dedicated equipment if possible

      • Use dedicated fittings and connections to avoid unloading a material to the wrong storage tank

      • Rotate inventories for materials that can degrade or react over time

      • Pay close attention to housekeeping and fire prevention around storage and handling areas

      • Some operations will need to be contained within special blast-resistant enclosures

      • Have an emergency response plan in place and conduct periodic drills

4. CHEMICAL REACTIVE HAZARD ASSESSMENT TOOL (CRW4)

   Catastrophic incidents resulting from unexpected chemical reactions continue to chemical reactive or incompatibility of the chemicals in the chemical industry. These catastrophic incident occurrences are due to avoidable leaks and spills, wrong chemical added, improper waste management, heels in containers, and even using the wrong absorbent to mitigate spills. Property loss, environmental damage, and personal losses including reputation and health can result from such issues. In order to prevent accidents, chemical compatibility should be a major factor in the chemical business anywhere two or more chemicals have the potential to interact, whether intentionally or accidentally. The Dow Chemical Company, The Center for Chemical Process Safety (CCPS), Materials Technology Institute (MTI) and other industrial/academic/government volunteers, a fourth version of the CRW (CRW4) has been developed. [3]

   Reactivity is the tendency of substances to undergo chemical change, which can result in hazards such as heat generation or toxic gas byproducts. The CRW predicts possible hazards from mixing chemicals and is designed to be used by emergency responders and planners, as well as the chemical industry, to help prevent dangerous chemical incidents. CRW current chemical database provided 5,000 specific chemicals and 68 reactive functional groups. These groups into mild and strong categories it allowed the reported hazards to be more representative of standard temperature and pressure conditions. Reactive groups provided information about flammability, reactivity, toxicity data. Specific chemicals are search based on the CAS no., UN no., Chemical formula & DOT lable etc. We get information about general description, reactivity profile, health hazards, water & air reactions, NFPA diamonds of specific chemical.

   Materials of construction (MOC) issues are a major cause of accidents in the chemical industry. CRW provided compatible material of construction (MOC), Mixture report, Compatibility charts.

   The new version of the free Chemical Reactivity Worksheet tool (CRW 4.0) is available through CCPS site

   (http://www.aiche.org/ccps/resources/chemical-reactivity-worksheet-40),versions included for both Windows and Mac.

   The software CRW was utilized in Xiangshui Chemical Co incident investigations process for identify and analysis incompatibility data of various chemicals which one involved in the fire accident.

   CRW used to investigate whether the first fire was caused in the warehouse because of DNB contamination with impurity. By considring that chemicals produced in the Xiangshui Chemical Co., can be analyzed using the incompatibility software CRW, an incompatibility table was established in Fig. 2 A large number of incompatible chemicals or incompatible reactions can be coincidentally encountered in the warehouse, thus the exothermic incompatibility accompanying the delivered heat could become a potential ignition source. [4]

   Figure 3 – Incompability chart of various chemicals produced and used in Tianjiayi Chemical Co.

5. CONCLUSION:

   The chemical reactive hazards involved in Swimming Pool Chemical Plant Fire incident and Napp Technologies facility incident. By using CRW4 software, prepared chemical compatibility chart and hazard summary of every compound involved in both the incidents. As per incident investigation of both the incident mentioned water contact with process compound is cause of the both the incident. By using CRW software, proved that water is incompatible and highly reactive with both the incident. In Swimming pool chemical plant incident, TCT chemical compound contact with water then reaction products may be corrosive, Reaction liberates gaseous products and may cause pressurization, Exothermic reaction at ambient temperatures (releases heat). Reaction may be particularly intense, violent, or explosive. In Napp technology facility incident, water is highly reactive with Sodium hydrosulfite, aluminum powder then reaction products may be corrosive, Reaction liberates gaseous products and may cause pressurization, Exothermic reaction at ambient temperatures (releases heat). Reaction may be particularly intense, violent, or explosive. CRW software predict flammable hydrogen gas may be release from this reaction.

6. REFERENCES

1. Swimming Pool Chemical Plant Fire Springfield, Massachusetts (June 17, 1988) incident investigation report, investigated by Richard L. P. Custer

2. EPA/OSHA Joint Chemical Accident Investigation Report, Napp Technologies, Inc. Lodi, New Jersey, EPA 550-R-97-002, October 1997.

3. Expanded Chemical Reactivity Worksheet (CRW4) for Determining Chemical Compatibility, Past, Present, and Future, James Farr, Dave Gorman, Dan Sliva, Al Hielscher, Trong Nguyen, George Baran, Brenton Drake, Emory Ford, Dave Frurip, Kirk Mulligan, John W. Ryan, and Dalina Viveros.

4. Case study on the catastrophic explosion of a chemical plant for production of m-phenylenediamine, Xiaodong Yang, Yongzhao Li, Yangqing Chen, Yuqi Li, Libo Dai, Ren Feng , Yih-Shing Duh, Journal of Loss Prevention in the Process Industries Volume 67, September 2020, 104232.

5. L. Johnson and J. Farr, CRW 2.0: A representative compound approach to functionally based reactive chemical hazards, Process Saf Prog 27 (2008), 212 219.

6. D. Gorman, J. Farr, R. Bellair, W. Freeman4, D. Frurip, and A. Hielscher, Enhanced NOAA chemical reactivity worksheet for determining chemical compatibility, Process Saf Prog 33 (2014), 418.

7. L. Bretherick, Brethericks handbook of reactive chemical hazards: an indexedguide to published data / edited by P.G. Urben; compiler M.J. Pitt , 6th edn., Oxford Boston: Butterworth-Heinemann, 1999, p. 1365.