Celebrating 50 years of the chemicals industry

Chemical incident series: eBook


We have been supporting the emergency services and the chemical industry from our conception in 1973 and over time we have gained a wealth of knowledge and experience from real-life incidents.


The aim of the series is to look at some of the biggest chemical incidents and their lasting impacts on organisational safety, response and regulation. Each incident has shaped how organisations perceive and manage risks today, and the series will look at the impact these have had on current chemical and safety regulations.

Our emergency responders go through the incident in detail and explore what the public and private sector can learn from these historic accidents now, highlighting the ongoing importance of robust risk management. 

We hope you find these case studies relevant and useful, and these inspire the incident safety expert within you!

The London Fire Brigade’s (LFB) single greatest loss of life incident since World War II took place in 1969, when post-fire checks on an empty vessel at the decommissioned Dudgeons Wharf oil storage facility triggered an explosion with fatal consequences for five firefighters and one site worker. The firefighters and site worker had unfortunately been unaware of the explosive atmosphere which had formed within the facility.

Today, the tragic events of Dudgeons Wharf rarely feature on lists of industrial chemical incidents, yet the lessons learned from the disaster led to the creation of the Emergency Action Code Scheme (also known as HazChem Code) in the UK. This introduced a marking system for chemicals that instantly communicates chemical hazards to emergency service personnel. The Emergency Action Code scheme is now managed by Ricardo – having been involved since the start – we think this is a fitting place begin recounting our 50 years of supporting the chemical industry. 

Dudgeons Wharf Incident

Dudgeons Wharf Oil Storage Facility1 was a facility located on the river Thames at the Isle of Dogs, Millwall, UK. It operated until closure in the mid-20th century and consisted of over 100 tanks and a total storage capacity of 30,000 tons of oils. It was during decommissioning after closure of the site when the tragic events occurred.

On 17 July 19692, work began to remove Tank 97, a cylindrical vessel with a total capacity of 500 tonnes fitted with a steel spiderweb roof. The vessel was designed to fail roof first so that in a failure scenario any fire or explosion would project upwards and away from people and property. Tank 97 had held myrcene but had sat empty for nearly a year and had been steam cleaned three days prior to removal.
The plan was to use an oxy-propane hot cutter to free the roof for removal, however during this operation smoke emerged from the vessel followed by a 20ft flame column erupting from the roof manhole cover. The LFB responded with three fire-engines supported by a foam tender and the Thames fire boat, but the fire had already been extinguished upon their arrival. 

The fire was thought to have been caused by the vessel’s construction material overheating during cutting. The fire service had a duty to ensure that the site was safe so as a precaution, soaked the vessel with water via a top access panel to minimise the risk of further fires. They also attempted to remove a lower access panel on the vessel to allow the fire service to conduct an internal inspection. 

Unable to remove the bolts on this lower panel, it was decided to cut out the panel, with five fire brigade personnel and one site worker remaining on the roof of the tank to continue soaking the vessel. As the cutting started, an explosion occurred within the vessel which ripped the roof straight off, with fatal consequences for all six men, and injuring five fire brigade personnel. 

Why did an empty vessel explode?

A lack of knowledge of what the tank had been used to store was a fundamental factor to the incident. It is thought that the tank had been marked with the word “turps”, but this marking alone would not have been sufficient to clarify the appropriate cleaning process that should have been used, or to provide information to feed into an assessment of risk levels during the decommissioning process.

The tank had contained myrcene which tends to polymerise when stored, forming a gummy residue on the surfaces of storage vessels. When steam cleaning operations are carried out on these residues they have been shown to break down, releasing flammable vapours which, when mixed with air, will form an explosive atmosphere. Either residual heat from the initial fire, or a spark from the cutting equipment used on the inspection panel, was therefore thought to have triggered the explosion.

The first iterations of Hazchem Codes were released after the events of Dudgeons Wharf, with Ricardo starting to work with LFB on the system they had devised in 19743. Hazchem codes were used to mark buildings in the London area where hazardous materials were used, with a similar scheme also starting in the Cleveland and Tees-side area. In the years since the incident there have been many developments to hazard classification of chemical products and marking and labelling of storage and transport equipment. The Hazchem Code has been further developed into the Emergency Action Code.

How would an Emergency Action Code be implemented?

The Emergency Action Code is two or three characters long and provides an instant response plan. The first number equates to an extinguishing media, the letter indicates appropriate PPE plus response tactics such as dilute, contain or reactivity. Occasionally a second letter is used to warn of a public safety hazard.

For Myrcene a placard, similar to that shown in Figure 1, would be displayed today during transport.


From this simple panel, a lot of information is shared:

  • The Red Class 3 diamond communicates flammable liquid.
  • The number 3 in the EAC advises foam, not water, should be used on fires.
  • The letter Y states that full firefighter’s uniform with self-contained breathing apparatus should be worn with any contained spillage to avoid entry to the environment, and also communicates a risk of violent or explosive reaction.
  • (UN)2319 corresponds to a terpene hydrocarbon.
  • The placards also include a telephone number to obtain more information, which can be provided by a specialist advice helpline, known as a Chemical Emergency Response service. 


How does Ricardo support the Emergency Action Code scheme?

Today, Ricardo are responsible for maintaining the EAC scheme which is published biannually as the Dangerous Goods Emergency Action Code List, in co-operation with the UK Home Office and published by The Stationary Office. In our 50th Anniversary year, we are delighted to have released the 2023 edition of the Dangerous Goods EAC List, available in print and digital version, accessible here.
During each update, feedback from regulators, emergency service personnel and industry is combined with our own emergency responders’ recommendations based on recent incidents. Having started as a UK scheme, the EAC is now also used in Australia and New Zealand. 

In future versions, we expect the Emergency Action Codes to be further refined to consider the environmental impacts of incidents, for example we are likely to see more scenarios where containment rather than dilute to wastewater is the suggested response. Similarly, there is a growing concern around firefighting foams that contain per- and polyfluoroalkylated substances (PFAS), which can be environmentally damaging and therefore impacts when they should be recommended. 


Although storage vessels are not in scope of EACs and the vessel was thought to be clean, the events of Dudgeons Wharf pushed the protection of emergency service personnel from chemicals into the spotlight, progressing the discussion of how to communicate emergency response procedures clearly and quickly when other sources of data are unavailable, such as on a road during transport.

Today the Dudgeon’s Wharf site is now part of a housing estate, with a memorial plaque for the six people who tragically lost their lives.  


Is your organisation prepared to prevent an incident? 

This incident raises several questions that are relevant to response today:

  • Are your staff able to interpret an Emergency Action placard if required?
  • What emergency response plans are in place, and is there capability to communicate both product information and actionable response advice on the chemicals involved to the emergency services and other first responders? 
  • Have your staff that work with chemicals had training in hazard awareness and are there people trained for first response? 
  • When transporting goods, do your vehicles display the correct placards?
  • Is your emergency phone number provision able to provide meaningful and robust advice, aligned to Cefic's guidelines for level 1 emergency response.  

The emergency services and chemical industry constantly face risks and challenges when managing chemical incidents. While such incidents are unfortunately difficult to avoid, when they do happen, access to emergency response support with rapid around-the-clock provision of expert advice in the callers’ local language will help reduce the impact of a chemical incident on people, the environment, assets, reputation and liability. 

Ricardo operates a market leading telephone emergency response service available 24/7/365. Our incident training experts complement this advice by supporting organisations to deliver safe, effective and competent emergency responses to hazmat incidents.


  1. Dudgeon’s Wharf – You Couldn’t Make It Up. Isle of Dogs - Past Life, Past Lives. [Online] 13 February 2014. [Cited: 5 April 2020.] https://islandhistory.wordpress.com/2014/02/13/dudgeons-wharf-you-couldnt-make-it-up/.
  2. Looking back at the Dudgeon's Wharf disaster. London Fire Brigade. [Online] 17 July 2017. [Cited: 5 April 2020.] https://www.london-fire.gov.uk/news/2016-news/looking-back-at-the-dudgeons-wharf-disaster/.
  3. The Safet Transport of Hazardous Chemicals. Feates, F. S. and Cumberland, R. F. s.l. : Control of Hazardous Material Spills; Proceedings of the 1974 National Conference on Control of Hazardous Materials, 1974.

Back to top > 


Download our chemical incident eBook now

ER Phonecall

Our chemical incident series is also available as a free download.

Download the eBook now

More related to chemical risk

Chemical Storage

How emergency responders can make or break effective response

Understand how the support and guidance provided during an incident can minimise the impact - and therefore cost - of an incident.

ER And Sdgs

Supporting the UN Sustainable Development Goals with emergency response

Telephone emergency response is about more than compliance. It is a powerful means to demonstrate your organisations' commitment to sustainability frameworks, such as the UN Sustainable Development Goals and other interlinking sustainability initiatives, like Responsible Care®.

NCEC Stories Emergency Response

How emergency responders can make or break incident response

Core to any emergency response service is the ability to provide effective help to those involved in an incident. At Ricardo, this means not just providing ‘information’ from the Safety Data Sheet (SDS) but applying our depth of knowledge and experience to provide actionable advice tailored to the circumstance and the caller at the scene of an incident.