Chemical dosing and storage systems

In many plants that I visit, I observe that many operators of chemical storage tanks and dosing systems do not follow certain basic precautions for avoiding incidents. Greg Humm of West Yost associates has a good presentation on the basic safety requirements for chemical storage and dosing systems.This is applicable for all industries including water treatment. See the presentation in this link. (PDF file - be patient!)

Managing risk in the chemical industry

With strategies of chemical companies always evolving to changing circumstances, I often find that "de-risking" strategies are often applied from a purely financial point of view rather than a combination of financial and process safety risks. In chemical industries, process safety risks need to be carefully studied and evaluated, as a single process incident could wipe out all the gains that you had obtained by de-risking purely from a financial point of view. Similarly, during mergers and acquisitions of chemical companies, process safety risks need to be carefully evaluated. It may cost you more if you do not heed process safety risks.
See BASF's approach to managing process safety risks in this link.

Operational excellence - an example

Chevron's tenets of operation is an excellent example of what process safety management should be! Their tenets, which I am quoting from this link in their website are

1. "Always operate within design and environmental limits.
2. Always operate in a safe and controlled condition.
3. Always ensure safety devices are in place and functioning.
4. Always follow safe work practices and procedures.
5. Always meet or exceed customers’ requirements.
6. Always maintain integrity of dedicated systems.
7. Always comply with all applicable rules and regulations.
8. Always address abnormal conditions.
9. Always follow written procedures for high-risk or unusual situations.
10. Always involve the right people in decisions that affect procedures and equipment".

I specially like the  last tenet. I see many companies NOT involving the right people in decisions that affect procedures and equipment.

Emergency headcounts

During a trip to Singapore, I saw an interesting LCD display outside a very large shop with many entrances and exits. This signage is posted at all entries. It warns  visitors that it is unsafe to enter when monitor turns red! (Approved load is 431).

Emergency scrubbing systems

It is very important to design your emergency scrubbing systems properly. If not, they will fail you when you need them the most. Croll Reynolds has a case history of "a relatively uncomplicated but effective method for handling large runaway emissions of TDI and solvent vapours. "
Read it in this link.

OSHA proposes fines

A news article mentions the following : OSHA has proposed fining a company $119,000/=  for 17 serious safety violations. These include "allowing cylinders to be exposed to physical damage; having inaccurate field verifications on tanks and values; using equipment that was not in compliance with recognized and generally accepted good engineering practices; failing to have clear written operating instructions for processes such as unloading hydrogen fluoride into storage tanks and switching storage tanks; failing to address human factors in relation to remote operating valves on the hydrogen fluoride storage tanks; failing to document and resolve issues addressed by the process hazard analysis team; failing to establish written procedures to maintain the integrity of process equipment; failing to implement written emergency operating procedures for emptying hydrogen fluoride tanks; failing to perform appropriate checks and inspections to ensure equipment was properly installed; and failing to establish and implement written procedures to manage changes to process chemicals, equipment and procedures. The company also was cited for a deficient incident report that did not include factors contributing to the vapor release and the recommendation resulting from the internal investigation. "
Read the article in this link.

Reactor Blast kills two

A reactor blast at a unit in Ankleshwar has killed two persons. Times Of India reports that "R S Ninama, additional district magistrate of Bharuch, said, "Preliminary investigations have found that the blast was caused by overheating of the reactor. The industrial safety department will investigate the accident and find out if safety has been compromised".
While I am not speculating on the cause of the incident, ensure that you are aware of the following:
Reactive chemical incidents are on the increase. Reasons are attributed to:
1. Lack of knowledge on process chemistry
2. Lack of knowledge on designing relief and vent systems
More and more companies are relying on in house R & D to develop new products. Unless you have a good system of ensuring that process safety is taken care of during the scale up from R & D to pilot plant and manufacturing plant, a disaster is waiting to happen.

Read the article about the incident in this link.

Electric heaters + Flammable material = Fire!

A court in UK has imposed a fine of 1.24 million pounds for an explosion in a tank in a gas terminal. A press release from HSE UK mentions the following:

"Investigators traced the cause of the explosion to a leak of highly flammable hydrocarbon liquid into a part of the plant responsible for treating waste water before discharging it into the sea.The leak was caused by the failure of a corroded metal separator vessel, which allowed water contaminated with the highly flammable condensate to enter a concrete storage tank where it was heated by an electric heater. The heater's elements were exposed within the tank, raising the surface temperature significantly causing the explosion and fire"
Read the press release in this link

Global warming and process safety

Just like the scare caused by the Y2K bug, today, chemical industries need to factor in the changes in weather due to global warming. The CSB narrated an incident where there was a propane release due to water freezing in a piping dead leg due to unusually cold weather. When the ice formed, the pipe expanded, cracked and later, when ambient temperature increased, propane came out of the crack and caused a major fire.
A news article reports another incident where a chlorine release occurred due to the freezing of a regulator due to cold weather. Though in India, we do not face such low temperatures, chemical operators must make themselves familiar with the pour points of liquids. Maybe in the not so distant future, we will be having snow and ice in India too!
Read the incident in this link

P2S5 accident

Dr Michael Fox has narrated an incident where a worker apparently inhaled P2S5 dust. he mentions that "When P2S5 enters the lungs it reacts with the moisture in the lungs and forms H2S. Only a very small particle of P2S5 is needed to produce a toxic concentration of H2S once inside the lungs. "
Read the incident in this link.
There are other incidents also which can be viewed from the above link.

Hypochlorite + urea explosion

For my friends in the fertilizer industry, Dr Michael Fox has narrated an interesting incident where an explosion killed one person. The explosion occurred when 12.5% sodium hypochlorite was being unloaded into a tank that previously contained a liquid fertilizer consisting of 78% urea and sulfuric acid (1:1 ratio). His investigation found out that when "liquid fertilizer was added to an excess of sodium hypochlorite, an extremely vigorous reaction plus significant heat was generated. One possible explanation seemed that when there is excess of alkaline sodium hypochlorite, the sulfuric acid is neutralized and what remains is sodium hypochlorite and urea, a mixture said to produce explosive nitrogen trichloride "
Read about the incident in this link.

Explosion proof and intrinsically safe fork lifts

The Hunstman Corporation has reported that it has recently completed an upgrade of their forklifts used in their Chinese facility to meet Chinese standards. The article mentions the following:
"The firm originally imported all of its explosion proof equipment from Europe to comply with EU standard (EN1755:200), American standard (UL NEC500/505) and International standard (IEC). However China only accepts its own in-house standard when accrediting explosion proof equipment.
As a result of this all equipment had to go through system upgrade to ensure that it was up to the Chinese “General Principles for Explosion Proof Industrial Trucks in Explosive Atmospheres” (GB19854-2005). A representative for Huntsman and the factory said:
“The aim was to conduct an overall system upgrade on the European converted explosion proof trucks to meet the Chinese national standard.”
The importance of using explosion and intrinsically safe equipment in potentially unsafe environments is vital, especially when transporting raw materials as is the case in the Guangzhou plant. On vehicles such as forklift trucks components such as the ignition must be adapted to prevent any spark or heat that could cause safety concerns when in the working environment.
The representative added: All the requirements of explosion protection safety management and safety supervision were considered, including, for example, the design and installation of Exd batteries and Exd lights, rewiring of Exd enclosures and changing the start-up battery on the diesel trucks.”
 Read the article in this link