Perhaps the most daunting task at hazmat emergencies is accurately and properly assessing the risk for responders. This is especially true for chief officers in command of field personnel and is a large component of the burden of command.

This trepidation can result from a general lack of knowledge of hazardous materials and their chemical and physical qualities, a lack of incidents at which to practice the art of risk assessment, and an absence of the comfort factor because many responders and chief officers feel out of their element.

Seasoned responders are not immune from the wide-eyed, deer-in-the-headlights look while at hazmat events. Many seem to be overwhelmed and don't know what to do despite training sessions. Coupled with the anxiety of the moment, responders also may suffer from analysis paralysis, in which an exorbitant amount of time is spent trying to figure out the nature of the hazardous material that's been released or in simply overthinking the situation. These issues can add up to very inefficient responses and potential public relations problems.

Too much precaution?

Risk can be defined as the probability, or chance, of harm occurring. In the emergency response field there's abundant risk, but through knowledge and experience we have learned how to manage it and proceed safely.

This is also true in hazmat response, as we have many administrative controls in the form of state and federal regulations, standard operating guidelines, site safety plans, and checklists. We employ the use of environmental monitoring to characterize atmospheres; we use state-of-the-art chemical suits, boots and gloves; and we use well-designed mechanical devices such as positive-pressure blowers, non-sparking tools and specialty leak-sealing units. We also employ fantastic computer-based research software to characterize the hazardous materials.

With so much technology in our favor, it's a wonder why many teams still seem to have a problem with mitigating a hazmat event in a timely manner. Although some teams enter the hot zone in as little as 30 minutes after arriving on scene, many teams still take well over an hour to do so.

One reason for excessive delays in hazmat response may be due to the precautionary principle, which is merely the academic term for “better safe than sorry.” When hazmat was new, and therefore unfamiliar, there was a fear instilled in many responders by some of the early hazmat texts. In the 1970s a popular battle cry was, “If you don't know, don't go, for it may blow!” No wonder there was a reluctance to engage with the monster of hazardous materials. Fortunately, explosions don't occur at every hazmat release, but paralyzing and irrational fear still overwhelms many hazmat responders. American essayist Randolph Bourne stated in his 1913 book Youth and Life that “We can easily become as much slaves to precaution as we can to fear.”

Knowledge breeds comfort

So how can responders and chief officers turn fear into warm, fuzzy feelings concerning risk assessment? Knowledge of the monster is paramount! All responders need to become well-versed in basic chemistry and know how to interpret data from software. Personnel also need to know the physical characteristics of a material and understand those parameters and the associated terms, such as boiling point, flashpoint and vapor pressure. These skills need to be maintained and honed to become competent, confident, and comfortable responders.

Risk Assessment Worksheet

Level of risk	1: Lowest	2: Low	3: Medium	4: High	5: Highest
Physical parameters
State/matter released	Solid	Liquids	Liquids	Liquid/gas	Gas
Material temperature	Room	Room	+/- Room	Hot/cold	Extreme
Chain length	Very long	Long	Medium	Short	Very short
AMU molecule size	Huge	Large	Medium	Small	Very small
NFPA reactivity	0-1	0-1	1-2	2-3	4
Boiling point	None	Very high	Moderate	Low	Very low
Corrosive/pH	6-8	5-9	4-10	3-11	<2, >12
Flashpoint (°F)	None	>140	100-140	<100	<0
Flammable range	None	None	Small	Medium	Wide
NFPA flammability	0-1	0-1	1-2	2-3	4
Ignition temperature	None	Very high	Moderate	Low	Very low
Oxidizer class	NFPA 1	NFPA 2	NFPA 3	NFPA 4	Org. per.
Radiation	None	None	Contained	Little	Yes
Vapor density	None	Heavy	Slightly heavy	+/- air	Light
Vapor pressure	None	Very low	<100	100-760	>760
Presence of fire	No	No	No	Near	Yes
Weather
Ambient temperature	Below FP	Near FP	At FP	Above FP	Far above FP
Humidity	Low	Low	Moderate	High	Very high
Time	Night	Night	Night/Day	Day	Mid-day
Wind	Low	Light	Moderate	High	Very high
Health
NFPA health	0-1	0-1	1-2	2-3	4
TLVs/PELs	None	High	Moderate	Low	Very low
IDLH	None	High	Moderate	Low	Very low
EPA signal word	None	Caution	Warning	Danger	Poison
AEGLs	None	None	None	High	Low
People	None	Few	Some	Multiple	Many
Animals	None	Few	Some	Multiple	Many
Exposures	Minimal	Small	Small	Multiple	Many
Intangibles	None	Few	Some	Multiple	Many
Container
Type	Plastic	Aluminum	Light steel	Medium steel	Heavy steel
Insulation	None	None	Carboy	Thermal	Cryogenic
Size/quantity (gal.)	Small	<5	<100	<500	>1,000
Leak rate	None	Low	Moderate	Heavy	Total
Damage to container	None	Little	Moderate	Heavy	Catastrophic
Fire impingement	No	No	No	Near	Yes
Sampling
Flammability	None	Low	10% LEL	<LEL	>LEL
Oxygen	Normal	<Normal	Reduced	19.5%	<19.5%
Toxicity	None	None/low	Low	<TLV	>TLV
Radiation	None	None	Contained	Little	Yes
Corrosivity	Normal	5-9	4-10	3-11	<2, >12

A double-walled, 55-gallon drum containing ethylene oxide (UN 1040) has been ruptured by rough handling at a medical products packaging company. The facility is in a remote part of town with no exposures other than a few people at the facility and some grazing cows in an adjacent field. The container has a 5-inch rupture along a seam and is leaking at a moderate rate onto a concrete pad. At 1000 hours, it's a clear day at 70°F with 45% humidity, and the wind is about 12mph. According to the Condensed Chemical Dictionary, ethylene oxide has a very low flashpoint, a wide flammable range, high vapor pressure and low TLV. Its vapor density is heavier than air.

The concept of knowing one's enemy is heavily stressed at our U.S. military academies, where Sun Tzu's The Art of War is required reading. For first responders and chief officers, the enemy includes fire, hazardous materials, weapons of mass destruction and more. Over time, this commitment to study and experience gained in the field will serve to quell fear and help pave the way for responses with the least time delay.

Because risk assessment is such a nebulous concept, many responders find it too much of an intangible to wrap their brains around. What's needed is a device that all personnel can use to better visualize risk and perhaps even make it tangible or concrete. Until responders can develop their own intuition or skills necessary for effective risk assessments, or even feel a gut or visceral reaction to a situation, they'll need a model to frame an event.

To assist responders in assessing risk and feeling more confident, I offer Petie's Comfort Level Scale on page 80, which converts the emotional and subjective feelings of risk for individual hazmat release situations into a numerical rating. While it's very difficult to quantify risk, and efforts to do so may oversimplify risk assessment, this scale is nevertheless offered to those who aren't comfortable in this area.

With the above limitations in mind, this scale can assist with categorizing a release and putting things into perspective. The scale also can assist with avoiding complacency and analysis paralysis, and it may help to speed a response up without compromising safety. Finally, keep in mind that the categories to consider when using the scale do not entail or account for the criminal element such as hidden timers, plastic or conventional explosives, and other terrorism concerns.

Risk level explanations

With a little practice, Petie's Comfort Level Scale can assist chief officers with visualizing risk and making more accurate assessments that lead to more efficient and safe responses to hazmat emergencies. Its numerical rating scale quantifies risk for a situation based on the identity of released material, chemical and physical hazards of the material, environmental conditions, and other factors. Responders can rate up to 40 individual factors to get a ballpark feel for the risk and assess a risk on the scale.

Remember, each and every situation is unique and therefore must be evaluated at the time of release. Risk assessment is also a dynamic evaluation that needs to be re-assessed frequently. This scale is offered in the hope that it helps all responders to get a grip on risk assessment.

For each hazardous material released, complete a worksheet and strive to rate each of the 40 risk factors. Simply circle or highlight the value you would assign for each risk factor. Data sources such as Material Safety Data Sheets, computer printouts and NIOSH pocket guides will be needed to research values. Most of the categories are self-explanatory, but if a category can't be determined or doesn't apply, simply skip it.

Risk increases from left to right in each category on the worksheet. Risk factors to evaluate within the Intangibles category include but are not limited to explosive material under fire impingement; polymerization reactions; radiation releases, including dirty-bomb scenarios; organic peroxides above their self-accelerating decomposition temperature, or SADT; crystals found near the valves or container openings; incidents involving chemical or biological agents; acids reacting with metals to produce hydrogen gas; and confined spaces or confined-space rescues. These components may be weighted more heavily than other risk factors.

After you complete the worksheet, look at the big picture and determine under which one of the five scale numbers most of your risk factor values fall. This will be the ballpark risk assessment for your hazmat event at that point in time. Risk factors selected above or below your ballpark assessment may influence bumping your rating up or down. Compare your rating with the scale numbers and categories below, along with some possible actions for response.

Level 1: Lowest Risk

Description: “Snoozer.”

Possible actions: This type of release is most likely a non-event in that it probably isn't a hazmat emergency. A course of action may be merely securing the area and calling for an approved environmental contractor or appropriate governmental agency. A single fire company most likely could handle this.

Level 2: Low Risk

Description: “Not a big deal.”

Possible actions: This type of release involves heavy liquids that do not vaporize readily but still may be poisonous or environmentally hazardous, such as oil, diesel fuel, mineral spirits and pesticides. Small releases may be mitigated by a few fire companies, but large releases will need private contractors and most likely environmental agencies to oversee. This type of release may not be an emergency, but it can present other hazards at the scene such as visibility and traction problems. A hazmat team may stand by for consultation.

Level 3: Medium Risk

Description: “You've got my attention!”

Possible actions: This type of release may involve heavy to light liquids that vary a great deal in chemical and physical qualities. The release may be flammable, which increases risk dramatically. Even small amounts of released material can present an emergency that requires several fire companies, the hazmat team, contractors and environmental agencies to mitigate.

Level 4: High Risk

Description: “Houston, we have a problem!”

Possible actions: This type of release may involve light liquids or gases which produce large amounts of vapor that may produce health hazards or flammability. Areas may have to be evacuated because of the vapor hazard, and many responders and specialized personnel may be required on site. The release may even involve fire and/or chemical reactions. Fire companies will be supporting the hazmat team.

Level 5: Highest Risk

Description: “180 RLH!”

Possible actions: This type of release is an all-out emergency: “180 RLH” means turn around and run like heck! This is Armageddon, where the best course of action may be to watch from a distance until all reactions stop or the fire burns out. A great deal of wisdom needs to be employed here. Fortunately, these types of events are very infrequent.

With these risk descriptions and possible actions in mind, refer to the worksheet on page 76 and its accompanying scenario. See if you agree with the assessment. Ultimately you need to do what's prudent and acceptable within your present situation and SOPs.

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A 23-year veteran of the fire service, Lt. David F. Peterson is the training and operations coordinator for the Madison (Wis.) Fire Department's Level A Regional Hazardous Incident Team. An adjunct instructor for the National Fire Academy, the Emergency Management Institute and the Environmental Protection Agency, Peterson is also the founder and a past president of the Wisconsin Association of Hazardous Materials Responders Inc.