Milk powder or anthrax? Why you need a chemist in your pocket
When fire crews attend incidents involving unknown, potentially hazardous materials, Hazmat officers are called on to perform complex chemical analysis, often in high-pressure situations. In this article, Dan Haggarty, Head of Emergency Response for the National Chemical Emergency Centre (NCEC), explains how 24-hour support from a team of trained chemists helps officers to accurately identify unknown materials and implement safe and proportionate response.
When attending a chemical incident, fire officers must be prepared to encounter a vast number of unknown substances, each with diverse hazards and handling procedures. Identifying materials at the scene is essential to resolve an incident safely and with minimum impact to the public.
Officers have a variety of analytical tools and techniques at their disposal for chemical analysis. This includes powerful detection, identification and monitoring (DIM) equipment, which is increasingly relied on for material identification.
However, the precision of these tests, and the reliability of the results, depends on the type of material being measured, the level of contamination and the environment in which it takes place. For example, it is not unheard of for harmless materials containing proteins, such as milk powders, to return false positives for biological weapons. Even when a material is identified with confidence, officers still need to select an appropriate handling procedure to safely resolve the incident.
Hazmat officers therefore face a complex task. Identify the material incorrectly and they put their crews and members of the public at risk. Take too broad a response and they risk causing unnecessary disruption and deploying high value personnel and equipment inefficiently.
NCEC provides 24-hour chemical emergency response on behalf of the UK Government to the UK’s blue light services. It also provides Fire Services in Ireland, Australia and the Middle East with chemical identification and emergency response support.
Each year, NCEC’s emergency responders receive almost 300 calls from fire officers across the world requesting expert support handling chemical incidents. Here, Dan Haggarty explains the steps his team of trained chemists take to identify hazardous materials and advise fire crews on the most efficient and effective response.
Chemical identification from elemental observation
DIM equipment is based on infra-red or mass spectrometry technology and provides an incredibly powerful analytical tool to identifying unknown compounds. However, when used in the field it will rarely produce a single, unambiguous match for the material being tested.
The need for rapid response at the scene means that officers do not have time to run more accurate lab based analysis. Even with this luxury, lab based tests can still be inconclusive, particularly when testing contaminated or clandestine materials.
DIM results aren’t the only piece of data that NCEC’s chemical emergency responders use to identify materials. They correlate this with other information provided by the Hazmat officer from the scene, and use their chemical knowledge to identify the most likely culprit. This is where more fundamental tests provide a lot of value.
The first is simple observation. Colour, appearance and physical state tells the chemical emergency responder a lot about the material before any analytical techniques are applied. In many of our calls we have been quick to inform the officer that the label on the container does not match the contents allowing the incident to move forward more effectively.
Where appropriate, simple analytical experiments can also be carried out, carefully, with appropriate personal protective equipment (PPE).
Litmus paper can be used to determine whether the material is acidic or basic and officers can use a vial filled with water to determine water solubility. Many organic materials will not dissolve into water and may form a second layer so we can narrow down whether the material is organic or inorganic. Where the layer forms will also give us a clue regarding density of the material as well since materials such as dichloromethane are heavier than water.
This chemical knowledge is supplemented with NCEC’s 40 years of experience responding to chemical incidents. Understanding the context of an incident enables the chemical emergency responder, to advise on as what materials are likely to be found in hazardous environments, such as in the manufacture of clandestine drugs or explosives.
However, identifying the materials is only the first step. Hazmat officers must also determine the most effective and proportionate response to resolve the incident as quickly as possible.
Evaluating an appropriate response
The hazards posed by chemical substances vary substantially depending on nature of the incident and the volume of material encountered. However, many processes for handling hazardous materials are based on ‘worst-case scenario’ situations. Following these in every situation is not an efficient use of resource. In some cases, it could even can be more dangerous than taking a nuanced approach.
While crews must be prepared to tackle major chemical incidents, they are statistically much more likely to be called out for spills less than 1 litre in volume. By considering hazards not only in terms of chemical properties but also in relation to spill volume and environment, fire services can select precise response procedures and avoid unnecessary deployment of personnel or equipment.
Proportionate response can improve response times at each stage of a chemical incident handling lifecycle, particularly during decontamination. Knowing when to thoroughly decontaminate equipment and collect run off water or simply wipe down a dry suit translates to a significant saving in time, freeing resources for more valuable deployment.
This advice must only be provided by a credible and trusted source, as mishandling even a pin drop of some chemical substances can have tragic consequences. NCEC chemical emergency responders are trained to provide proportionate telephone advice to streamline the response.
NCEC’s industry leading hazardous chemical database, Chemdata®, also helps fire services to cut the time and cost of identifying chemical materials and the appropriate handling procedures.
Designed for use in moments of emergency, Chemdata is a global, multilingual tool that provides instant access to detailed information on over 61,000 chemical substance and 176,000 product names. Available on desktop, iOS and Android operating systems, Chemdata provides practical and proportionate advice to help fire services make split second decisions in hazardous chemical environments, whether implementing snatch rescue operations or responding to minor or major spills.
Chemdata is developed with the direct input of fire service and emergency responders from around the world. For over 30 years the system has provided industry leading information on the chemical hazards and reactivity, necessary PPE, precautionary actions, environmental priorities and essential first aid required to handle chemical substances. Chemdata also provides general advice on contemporary topics in incident response. This includes advice on emerging trends in the chemical industry, including fuel cell and clean transport technology, and guidance on handling unusual incidents.
From the NCEC call log
We received a call from a fire and rescue service officer dealing with an incident where a suspicious package had been found on the motorway. The officer wanted help in identifying the material contained in the package and required prompt advice since the motorway had been closed in both directions. The bomb disposal unit had checked the package and found no evidence of explosives so had handed the incident back to the fire and rescue service.
Our emergency responder advised the officer over several calls the ‘best fit’ for the material as more information came to light. The incident had been ongoing for some time when the first call was placed to NCEC for assistance and the chemical emergency responder was aware of the need for swift and relevant information. The packaging itself did not relate to the material so the officer conducted the litmus and starch paper tests alongside measurements by the local DIM team. These tests allowed the responder to identify potential candidates for the material, which the fire and rescue service used, so that handover to the motorway authorities could be achieved.
At NCEC, our national role always keeps us on our toes. Due to extensive training and experience, our emergency responders are confident in adapting to situations as they arise meaning we can always provide advice as necessary. In this case our emergency responder could narrow down the possibilities from the data gathered using their experience and extensive chemical knowledge.
NCEC has provided expert 24-hour chemical emergency response for over 40 years; working with emergency services personnel across the world to effectively handle and reduce the impact of hazardous situations.
For more information, go to the-ncec.com