Since the 1980s, there have been big gains in the knowledge of chemicals and how they impact public health and the environment. But that doesn’t mean that everyone is confident in their level of knowledge or training.
I recently spoke at the 2015 International Network of Environmental Forensics conference in Toronto on an approach to site and workplace safety that uses a quick-check system to identify and verify the chemical properties of labeled, unlabeled, unknown or mixed substances. I also outlined how the quick-check test system must be part of a disciplined approach to an incident to protect life, property and the environment.
Environmental forensics is used in determining causes and sources of chemical releases to the environment. So it’s very important that forensic investigators know how to approach a spill site, whether in a lab, a factory or in the outdoors, in order to keep themselves, the property and the environment safe. While their scientific knowledge may be totally up to date, there is still a need for the first-hand, practical information we’ve gained and procedures we’ve developed over the years.
The quick-check system uses pH paper, starch paper and a source of clear flame, such as a Bunsen burner, or portable ignition source. Detectors for combustible gases and other meters can be included for specialized monitoring.
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In less than a minute, responders can determine the chemical properties of corrosives, flammables and oxidizers. The sensitive pH paper and starch paper can also be used to detect corrosive atmospheres.
But the quick-check system isn’t a complete answer to response safety. If responders are not putting proper site safety measures into place and taking a disciplined approach to entering a site, the results of the quick-check system may come too late to save a life or a structure.
The disciplined approach relies on a set of Golden Rules for approaching a scene:
- Never assume anything!
- Suit up to protect entry routes to the body from toxic substances.
- Work clean, to prevent cross contamination and any adverse reactions that can result.
- The disciplined approach also revolves around ASIA-R:
- Approach the scene with knowledge, experience and caution.
- Secure the scene to keep out unprotected and unnecessary personnel.
- Identify chemical properties by testing, using small to trace amounts of substances.
- Assess risks and hazards.
- Respond or take appropriate action to modify conditions and test, verify and assess danger factors.
Following a disciplined approach from the beginning of an incident will help ensure representative samples are collected and tested at the scene, or sent for analysis safely. Samples can be pure chemicals or the results of an explosion in a laboratory where 20, 30 or 40 chemicals combine to become a new product that presents unknown challenges. The products may just be waiting for the right condition to create unwanted off-gassing, heat, fire or an explosion.
For instance, first responders may be uncertain about putting water on a chemical spill because it may escalate the situation to generate heat, rapid burning or even a detonation. That type of delay while determining an appropriate response can have serious consequences that can cause injury or death, while damaging property and the environment.
In the hands of trained responders and investigators, quick-check chemical tests can provide accurate and objective information on the properties of known and unknown chemicals and chemical compounds. The process removes the danger of speculation or guesswork and helps responders deal with the actual properties of what they are facing. Then, they can choose appropriate personal protective equipment for the situation.
Emergency guidebooks and Material Safety Data Sheets really only provide enough information to ask the questions about the risks, hazards and surprises responders may have to face. By obtaining a few drops of a liquid solution or a few grains of dry powder as a sample, responders are in a position to identify, verify and assess the physical properties of the materials they are dealing with.
Physical testing and evaluation of chemical properties should be carried out at each step, from the initial response through to spill response, recovery and site remediation.
There are instances where the dangerous properties of chemicals may not be obvious at all, because they are found commonly in households, factories, laboratories and even schools. These are household cleaners and drain cleaning products that can contain 50% sodium hydroxide (caustic) with little to no smell, and 93% sulphuric acid with a density almost twice that of water. Both corrosives are more reactive at elevated temperatures and can destroy skin tissue and cause irreparable damage to the body.
I’ve been applying hard science to testing chemicals since the 1970s to deal with both known and unknown laboratory chemicals and to accurately determine chemical properties for safe handling and transport of materials for disposal or treatment.
It was not uncommon in the 1980s to be involved at digs on the grounds of institutions that had buried waste chemicals on-site because they were too dangerous to dispose of through traditional methods. It was vital to everyone’s safety to determine if the contents of containers were stable, since high-risk and unstable chemicals could be sensitive to heat, friction, shock or sunlight. A 500 ml bottle of some substances could go off with the force of a stick of dynamite.
In those days, physical testing of known and unknown chemical properties could involve putting a few drops of a liquid on the end of a paper towel and trying to ignite the substance to determine the risk of combustion, or rapid burning by observation. When pH paper replaced the paper towel, it allowed chemical substances to be identified as either acids, bases or neutral, and whether they were non-flammable, combustible or highly flammable.
Concern about oxidizers, which could react with anything that burns to cause heat, fire and/or explosions, prompted the use of potassium iodide paper.