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Topic 61: Reactive Hazards

SanjayVyas's picture


Hazard is defined as a chemical or physical condition that has potential to cause harm to human life, property or the environment and a reactive hazard has potential to initiate a reactive incident. It is an outcome of changes to chemical structure leading to rapid release of energy, heat and gaseous products leading to severe consequences e.g. fire, explosion, or toxic release.

A reactive hazard may involve:

·        
Impact or thermal sensitive self-reactive
chemicals that may rapidly decompose resulting in a potential explosive release
of energy;


·        
Runaway reactions


·        
Chemical incompatibility between two or more
substances


Examples of uncontrolled industrial chemical reactions that
can be considered as potential reactive hazards are polymerisation,
decomposition, acid -base, oxidation reduction and reaction with water.


 
The severity of reactive hazards also depends on various
process conditions such as temperature, pressure, chemical concentrations,
impurities, catalytic effects, chemical inventory, etc.


Incidents from reactive hazards can severely affect workers
and the public and cause major economic losses and environmental damages. The
US Chemical safety and Hazard Investigation Board (USCSB) has information of
167reactive incidents out of which 48 caused a total of 108 fatalities with an
average of six injury related incidents. Two of the most serious industrial
accidents resulting from poor understanding/ management of reactive hazards are
Bhopal Accident, 1984 (>10000 fatalities and >500000 injuries) and Seveso
Accident at Italy, 1976.


HSE legislation and guidelines associated with Reactive
Hazards are;


·        
Health and safety at Work Act 1974,


·        
Chemicals (Hazard Information and Packing for
Supply) Regulation (CHIPS) – Risk Phrases.


·        
Dangerous Substances and Explosive Regulations
DSEAR


·        
Implementation of ATEX 137 Directives


·        
Control of Industrial Major Accident Hazards
(Seveso II Directive)


·        
CLP (Classification, Labelling, Packaging)
Regulations


·        
REACH Regulations


·        
NFPA 400 Hazardous Material code


·        
NFPA 704 Standard System for the Identification
of Hazards of Material for Emergency Response


·        
NIOSH Pocket guide to Chemical Hazards


·        
Centre for Chemical Process Safety (CCPS) –
Essential Practices for Managing Chemical reactivity Hazards


Management of reactive hazards is essential for safe design,
operation and maintenance of any oil and gas or chemical industry and mainly
involves thorough identification and evaluation of potential reactive hazards
and mitigation of associated risks.

Sanjay Vyas 


Comments

Michail.Sevasteiadis's picture

As Mr Vyas gave us a good overview of this issue, I would like to focus more on Reactive Hazards Management. There should exist a proper system in order to manage chemical reactivity hazards where information related with a specific chemical process are collected to identify the potential chemical hazard.Then reactivity should be tested for the risks to be assessed and should be followed by process controls and risk management options identification. The associated risks should be documented along with the proper management decisions and related training should be provided to the personnel. Operator's management practices should be often reviewed, audited and improved for better results achievement.

According to a U.S. Chemical Safety Board Report, 167 incidents of the period 1980-2001 led to 108 deaths and significant property damage. In more than 90% of the incidents, all the information that could prevent them was already documented and publicly available. Maybe even with a hazard management system incidents can not be completely extinguished.


References:

1) Johnson, Robert. W.; Rudy, Steven W.; Unwin, Stephen D., Essential Practices for Managing Chemical Reactivity Hazards, Center for Chemical Process Safety/AIChE:2003

Reactive chemical hazards are very harmful and dangerous. As
the US chemical safety board maintain may cases of that and deaths of people.

Esters Manufacturers in india   

Olamide s Ajala's picture

 

Ensuing from vyas discussion,I will elucidiate on prevention of reactive chemical explosions and runaway reactions .
Reactive chemical hazards have been a major trepidation for industries that process, handle, transport, or store reactive chemicals (Bretherick, 1987).
key chemical accidents cannot be banned exclusively through command and control regulatory requirements; understanding the major root causes of accidents, widely disseminating the lessons learned, and integrating these lessons learned into safe operations are the key to mitigating the hazards. . Detailed chemical kinetics of active materials is also essential to improve current systems, design new explosives, and control energy releases for process safety.
Steps for accident prevention
·    Chemical and process hazards must be understood and addressed.
·    All employees need to understand the chemical and process .
·    Standard Operating Procedures (SOPs) are essential to safe operations.
·    Employees must be properly trained in the processes they work on using the SOPs for that process or job tasks.

conclusively,It is important that EPA(environmental protection agency), SERCs, LEPCs, emergency responders and others  review and regularly audit the safety procedure for the transportation and storages of this hazardous chemical in industries  and take appropriate steps to minimize the hazard.

References
http://www.epa.gov/OEM/docs/chem/chiefinl.pdf
http://www.sciencedirect.com/science/article/pii/S0098135406001220
Olamide Sherifah Ajala
Student ID:51230562
Course:Sub sea Engineering
olamide.sherifah.ajala@aberdeen.a.uk

Alabi Ochu Abdulraheem's picture

Safety is the relative freedom from hazards. This means that in order to be safe, there is the need to identify the various hazards (threats) that could result to high risk which could jeopardise safety in a working environment. After recognition of the hazard, which could be achieved before, during and after an operation, an effective management system can be put in place to help improve safety. Some of the various techniques that could be deployed to recognise hazards are as follows:
Hazard Operability Study (HAZOP): This technique could be used at any point. It is a sensitivity analysis (what-if analysis) with the aim of identifying improper procedures, equipment, employee training, management systems in order to prevent or minimise the consequences of catastrophic release of toxic, reactive, flammable and explosive chemicals.
Incident Analysis: This technique could be used after exposure to the hazards and a consequence has occurred. It involves a “root cause analysis” which makes use of the fault tree analysis, multiple whys etc. to help keep the unwanted event from reoccurring.
Multi – Step Planning Process: This is a technique that could be used before the operation starts. It is all about planning to execute a job safely by asking some short questions that will make the employee consider the hazards and control associated with such job. Some of these questions are what am I to do? What do I need to carry out this job and how do I do it? How could I get hurt? What am I going to do to prevent injury?
Job Hazard Analysis:  Also called job safety analysis could be used during the operation (that is when the job is on). The analysis involves listing all the steps needed to carry out a task, the hazards involved in performing the task and the control measures for each mentioned hazards.
The management of hazard recognition system could be optimally achieved through planning, good leadership, organisation and control.
Before dotting the i’s and crossing the t’s I would stop and pose this question to my fellow colleagues “do you think an employee deserve the best hazard recognition management system?”
References
1) Watson J. L. “Effective Management System” SPE 26365, Houston, Texas, USA. 1993
2) David F. C. “Techniques for Hazard Recognition” ASSE, Orlando, Florida, USA. 24-27 June 2007.
Name: Alabi Ochu Abdulraheem
Reg no:51231595

OKEKE FRANCIS's picture

Reactive hazards are associated with chemical that explode or
catches fire on its own, with other chemicals or when exposed to water. The
main concern is the adequate control of these hazards. Reactive materials must
be identified and potential hazards mitigated. Some facilities having these
reactive materials have the hazards controlled adequately, some cannot
adequately control the hazards while others do not know the hazards
they pose.

The first step in handling reactive materials is first identifying,
labelling and knowing the ones that can cause a dangerous release under
different conditions. Personnel working with these materials must know the
reactive material handling procedure. The storage of the material must meet the
required specification. Reactive materials should be stored away from operating
areas in monitored and secure locations. Finally, emergency response plan must
be in place and routine safety drills should be carried out.

http://www.aiche.org/ccps/topics/process-safety-technical-areas/chemical...

OKEKE FRANCIS 

Savitha Haneef's picture

Reactive hazards arise directly from exothermic chemical reactions.Such reactions can lead to thermal run aways which happens when the heat of reaction exceed the heat being removed.This results in increased temperature in the container leading to a lose of control of the reaction giving no time for correction.Thermal run away may result in an explosion or release of toxic gases to the environment .Such a toxic cloud killed more than 10,000 in the bhopal gas tragedy.

A chemical risk assessment is required to prevent any such incidents.This involves defining the chemical process, identifying the hazards, evaluating the risks,selecting appropriate saftey measures and implementing and maintaining them.Inherent safety is the best safety measure here.It eliminates or reduce the hazard.Process control is another method which uses alarms or sensors helping for a manual intervention incase of a thermal runaway.And then protective measures which reduces the consequences.As far as I am aware , all these safety measures failed in the Bhopal gas tragedy.Refrigeration ,inherent safety method, to cool down the temperature, when a violent reaction occured by MIC mixed with water, failed.Alarms were turned off to by the operators not to create panic among the local people.The flare system ,protective measure, to burn the toxic gas was faulty and not repaired.These all factors lead to the highest industrial accident.What I understand from the Bhopal gas tragedy was the lack of awareness of the chemical process and how to deal with it in case of an incident.So training the operators and making them aware about the chemical process is very essential.

 

www.hse.gov.uk/pubns/indg254.htm

Savitha Haneef

MSC Safety & Reliability Engineering

Catriona Ogg's picture

Expanding on what my classmate Olamide has already mentioned, I think understanding the nature of reactive hazards is key to their prevention.  Employees will need to receive a full education of what initiates dangerous reactions with these hazardous substances and how severe the reactions can be.  The employer will need to provide full and regular training on the storage, handling and transportation of reactive hazards and ensure that only those who have received this training come into contact with them.
  Some of the general SOPs in place that will help reduce the risk include:

  • clear and accurate labelling of reactive hazards (including safety symbols)
  • use of material safety data sheets - communication of nature of hazard between supplier and consumer
  • PPE for those handling hazardous substances
  • adequate ventilation in areas where flammable liquids are used
  • suitable storage containers/conditions
  • substances with the potential to react with each other stored separately
Thomas Ighodalo's picture

a situation that perfectly with my subject is the texas fire disaster of April 16 1947 which initially started from a fire from the ammonia nitrate cargo hold which lead to one of the worst disaster recorded with the loss of  576 lifes and hundreds injured in
this city with only 16,000 residents within 16hours [1]

 So how dangerous is ammonium
nitrate? It is a commonly used fertilizer all over the world. Some documents described
it as a "highly explosive" material with the supporting evidence to
the texas city disaster
,  on the other hand, in
most safety data sheets published by ammonium nitrate manufacturers, ammonium
nitrate is said to be stable and when properly handled, and state that it is
perfectly safe to store and ship. It is interesting how the two sources can
have opposite views on the same chemical and yet both have convincible evidence
backing up the claim [1].

 These is where the concept of
reactivity comes into play, a material can only be made reactive if placed in
an environment created for such reactivity i.e you can not get a fire if the
three elements (source of ignition, Oxygen, fuel) required are not present.

Back to the Texas city disaster,
the reason for such a large mistake was a calamity of errors and poor judgement
i.e the ammonium nitrate kept on burning in an enclosed environment deprived of
oxygen and thus the temperature was raised and eventually exceeded the
decomposition temperature of 210 degree Celsius. A large quantity of ammonium
nitrate then decomposed and the result was an explosion [1]. One interesting point
is that because this decomposition reaction requires only ammonium nitrate and
heat, but not oxygen, the Captain's idea of suffocation lead to the first of a
series of explosions and mishaps.

In summarizing creating a hazard
out of a non reactive material and vice versa, has more to do with the
knowledge of the people handling the particular material rather than the
material itself.

 

 

 References:

1. http://nobombs.net/brucel/explosiveincidents.html#Texas%20City%20Disaste...

"Everything we hear is an opinion not a fact"

amaka.ikeaka's picture

A reactive chemical incident is a sudden event
involving an uncontrolled chemical reaction with significant increases in
temperature, pressure, and/or gas evolution that has the potential to, or has
caused serious harm to people, property or the environment [1]. Adequate
training should be given to workers on chemical reactivity hazards, as the
environment can only be secure if the workers are made to understand the
potential hazards and react appropriately to minimize or contain hazards. I
believe that companies that store, handle or process reactive chemicals on a
regular basis should have appropriate receiving and transferring practices in
place. For example, all connection points along pipes need to be clearly marked
so that chemicals would flow in the correct direction and do not accidentally
co-mingle [1].  Finally to be truly
prepared for a possible disaster, scenarios that could result in the accidental
release or explosion of chemicals should be documented, ensuring that a
remedial action plan is in place.

Reference

www.chemistry.ca/index.php?ci_id=3149&la_id=1

 

OKECHUKWU CHUKELU's picture

The consequences of reactive hazards can be
very severe and more than likely to lead to fatalities.  Such situations may result when incompatible
chemicals spill by accident, mix as chemical waste, or combine during the
course of experimental procedures. In order to be able to curb these risks and
their consequences, it is paramount to identify areas of possible deficiencies.
The most commonly recounted deficiencies are in; Operating procedures, safe
operating limits and trainings, hazard identification and evaluation, human
factors, emergency relief management and controls, process design, knowledge of
process and investigating incidents. Been able to identify these deficiencies
would go a long way in assisting facilities in managing the hazards of reactive
chemicals.

 

Ref:

1.    
http://www.epa.gov/osweroe1/docs/chem/reactive-management-pub.pdf

2.    
http://ehs.unc.edu/manuals/laboratory/docs/lsm11.pdf

 

Okechukwu Chukelu (51231798)

Ojo Oluwayimika Joseph's picture

As stated above in the previous comments, reactive hazards occur with a chemical that is flammable in contact with air or even sometimes on its own and this could gravely detrimental to safety. A  major question that should be asked before storage, handling or processing of chemicals should be if it could cause a reactive hazard. Attempts that have been made in this light to determine how reactive a chemical is based on molecular structure include the oxygen balance method, chemical thermodynamic and energy release evaluation (CHETAH) and calculated diabatic reaction te,perature (CART). There are limitations however with these methods and are still subject to laboratory tests for effectrive use. A more reliable experimental procedure is assessing the reactivity based on calorimetric analysis. This can be resource consuming and thus only possible for a limited number of compounds.

References

S.R. Saraf, W.J. Rogers, M.S. Mannan, Prediction Of Reactive Hazards Based on Molecular Structure

 

Ojo Oluwayimika Joseph

Oil and Gas Engineering

ASOKHIA BENJAMIN MUYIWA's picture

Almost every operation has inherent hazards associated. Operations with reactive substances and chemicals pose a hazard during execution. In the work by Coble (2007) different phases of hazard identification have been outlined.  This provides an industry perspective on how and when to recognize potential hazards.

 

Hazards should be anticipated even before exposure to the hazard. This would help to instil the knowledge of the risks posed by operations to the personnel. This perspective emphasizes the need for proper planning and review of upcoming jobs so as to provide a proper perspective on the associated hazards.

 

During exposure to such hazards, operation within standards and best practice would reduce the probability of an incident. At the end of such hazardous task, it is important to do a review of the entire task so as to identify incidences, near misses and possibility of improving hazard recognition if such task is to be performed in future. This review is carried out through debriefing of personnel that undertook the task with a critical evaluation of the work permit, procedures followed and checking for alignment with policies.

   

Reference

 

Graham A. Dalzell, 1996. “The Lifecycle Approach to Hazard Management”.

Society of Petroleum Engineers, Texas 1996.  David F. Coble 2007. “Techniques for Hazard recognition”. ASSE Conference Paper. 2007

ASOKHIA BENJAMIN MUYIWA's picture

Sorry this post is replaced by the next.

ASOKHIA BENJAMIN MUYIWA's picture

Almost every operation has inherent hazards associated. Operations with reactive substances and chemicals pose a hazard during execution. In the work by Coble (2007) different phases of hazard identification have been outlined.  This provides an industry perspective on how and when to recognize potential hazards.

 

Hazards should be anticipated even before exposure to the hazard. This would help to instil the knowledge of the risks posed by operations to the personnel. This perspective emphasizes the need for proper planning and review of upcoming jobs so as to provide a proper perspective on the associated hazards.

 

During exposure to such hazards, operation within standards and best practice would reduce the probability of an incident. At the end of such hazardous task, it is important to do a review of the entire task so as to identify incidences, near misses and possibility of improving hazard recognition if such task is to be performed in future. This review is carried out through debriefing of personnel that undertook the task with a critical evaluation of the work permit, procedures followed and checking for alignment with policies.

   

Reference

 

Graham A. Dalzell, 1996. “The Lifecycle Approach to Hazard Management”.

Society of Petroleum Engineers, Texas 1996.  

 

David F. Coble 2007. “Techniques for Hazard recognition”. ASSE Conference Paper. 2007

Bassey Kufre Peter's picture

Having taken part in a Radiography testing, I can categorically state that a reactive hazard- hazard due to chemical reaction is worst than most other forms of hazards.This is because at a given incident of it,thousands of people within that localities will be affected by its emission and its effect may not manifest at the immediate but causes gradual damage of the body system and in most cases it can result in permanent deformation such as impotency,blindness etc.Stringent mitigation measures such as total adherence to the HSE guidelines must be implemented so as to combat this menace, and implementation and monitoring team must be put in place to ensure that personnelinvolved in such activities do not cut corners thereby endangering their lives and that of others.

Bassey, Kufre Peter
M.Sc-Subsea Engineering-2012/2013
University of Aberdeen.

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