Hazardous Materials EmergenciesHazardous Materials Emergencies

Kent R. Olson, MD, FACEP

Medical Director, SF Division

California Poison Control System

Hazardous Materials EmergenciesHazardous Materials Emergencies

• Course Objectives: Describe common routes of exposure to

hazardous materials Differentiate exposure versus health hazard Discuss the concept of secondary

contamination and its implications for decontamination and triage

Describe pre-hospital and ED response to victims of hazmat exposure

Types of HazardsTypes of Hazards

• Physical Explosion Fire

• Poisoning Corrosive or irritant effects Systemic poisons

Physical States of Hazardous MaterialsPhysical States of Hazardous Materials

• Gas

• Liquid Vapor Mist/Aerosol

• Solid Fume Dust

Potential Routes of ExposurePotential Routes of Exposure

• Inhalation

• Skin & Eyes

• Ingestion

• Injection

Toxic EffectsToxic Effects

• Local injury Upper airway or lung injury Skin or eye burns Corrosive injury to GI tract

• Systemic effects Dizziness, nausea, vomiting Coma, seizures, arrhythmias Cancer, Reproductive effects

Case StudyCase Study

A 44 yo man spilled concentrated phenol on his legs and did not wash it off immediately.

In addition to the chemical burns, he developed agitation, confusion, and seizures.

Some Corrosives with Systemic ToxicitySome Corrosives with Systemic Toxicity

Agent Systemic Toxicity

Formaldehyde metabolic acidosis (formate)

Hydrofluoric acid hypocalcemia, hyperkalemia

Permanganate methemoglobinemia

Phenol seizures; coma; liver and kidney injury

Phosphorus liver, kidney injury

Silver nitrate methemoglobinemia

Inhalation ToxicologyInhalation Toxicology

• Irritant or corrosive effects Highly water soluble gases and vapors,

larger mists and fumes upper airway

Less soluble, smaller lower airway

Systemic effects Simple asphyxia

Target organ toxicity

Hazard is Determined By:Hazard is Determined By:

TOXICITY

and

EXPOSURE

Toxic + Significant Exposure = HAZARD

Toxic + No Serious Exposure = No Hazard

Dose-Response ConceptDose-Response Concept

“All substances are poisons; there is none which is not a poison. The right dose differentiates a poison and a remedy.”

- Paracelsus (1493-1541)

Dose is Determined By:Dose is Determined By:

• Route of exposure

• Amount

• Duration

Common Dose TerminologyCommon Dose Terminology

• Inhalation: ppm: parts per million ppb: parts per billion mg/m3: mg per cubic meter of air

• Ingestion, Injection, Skin absorption: mg/kg: mg per kg of body weight

• LD50 and LC50: Animal studies: 50% mortality dose

Examples of Acute Oral LDExamples of Acute Oral LD5050

Substance: LD50 (mg/kg)

Ethyl alcohol 10,000

Sodium chloride 4,000

DDT 100

Nicotine 1

Dioxin 0.001

Botulinus toxin 0.00001

Toxicity RatingsToxicity Ratings

Rating LD50 (oral) LC50 (4 hr)

Extremely toxic < 1 mg/kg < 10 ppm

Highly toxic 1-50 10-100

Moderately toxic 50-500 100-1,000

Slightly toxic 0.5-5 g/kg 1,000-10,000

Pract. nontoxic 5-15 10,000-100,000

Relatively harmless > 15 > 100,000

Workplace Exposure LimitsWorkplace Exposure Limits

Chronic average daily exposure:(8-hour Time-Weighted Average)

• TLV: Threshold Limit Value ACGIH recommended standard

• PEL: Permissible Exposure Limit OSHA enforceable limit

If the exposure is < TLV or PEL,

it is safe for Hazmat operations

If the exposure is < TLV or PEL,

it is safe for Hazmat operations

Workplace Exposure LimitsWorkplace Exposure Limits

Brief higher exposures:(20-30 minutes or less)

• STEL: Short-Term Exposure Limit

• C: Ceiling limit

• IDLH: Immediately Dangerous to Life or Health

Exposures in this range can causeserious injury - need protective gear

Exposures in this range can causeserious injury - need protective gear

Estimating Exposure RiskEstimating Exposure Risk

• Vapor Pressure Multiply by 1,300 to estimate maximum air

concentration in ppm from a liquid spill

• Vapor Density If > 1, vapor may collect in low-lying areas

• Warning Properties Odor Irritation

Methylene ChlorideMethylene Chloride

• Vapor Pressure = 349 mm Maximum air conc. = 453,700 ppm IDLH = 5,000 ppm

• Vapor Density = 2.9 Will collect in low-lying areas asphyxia

• Warning Properties Sweet, ether-like odor at > 200 ppm Olfactory fatigue may occur w/chronic exp.

Secondary ContaminationSecondary Contamination

Substance is toxicSubstance is toxic

. . . and . . .

Is likely to be carried on victim’sclothing, hair or skin

in sufficient amounts to threaten others

Is likely to be carried on victim’sclothing, hair or skin

in sufficient amounts to threaten others

Secondary ContaminationSecondary Contamination

Serious potential for contamination:

• Poisons with high skin toxicity eg, organophosphate pesticides

• Volatile liquids eg, methylene chloride

• Radioactive dusts or liquids

• Etiologic agents (viruses, bacteria)

Secondary ContaminationSecondary Contamination

Little or no risk of contamination:

• Gases eg, carbon monoxide

• Vapors (unless condensation occurs) eg, methylene chloride

• Non-volatile liquids with no skin toxicity eg, ethylene glycol (antifreeze)

Secondary ContaminationSecondary Contamination

Implications for Decontamination:

• Serious risk of secondary contamination: Decontamination is mandatory Decon may take priority over victim Rx

• No risk: Decon optional Victim treatment is priority

Case StudyCase Study

A 21 yo student spilled concentrated sulfuric acid on herself when the bottle slipped off the shelf.

Quiz: Your first management priority is: ABCs Give Diazepam Determine her insurance coverage Immediately wash thoroughly with water

Case StudyCase Study

A 32 year old farmworker was heavily doused with liquid parathion from a storage container. He is lying in a pool of liquid, and he is convulsing.

Quiz: Your first management priority is: Airway (ABCs) Diazepam for the seizures Atropine Rescuer protection & victim Decon before Rx

Case StudyCase Study

A 22 yo worker inhaled chlorine gas produced when he mixed bleach with an acid cleanser. He immediately developed severe coughing and wheezing.

Quiz: Your first management priority is: Criticize him for mixing the chemicals Give oxygen and bronchodilators Perform thorough Decon BEFORE Rx

Basic Goals for EMS Hazmat RespondersBasic Goals for EMS Hazmat Responders

• Recognize Hazmat incident

• Protect yourself & others

• Identify toxic material(s)

• Determine toxicity and hazard

• Use appropriate protective gear

• Decontaminate before transport

• Provide specific treatment

Hazmat Scene ZonesHazmat Scene Zones

Spill

HOT ZONEHOT ZONE

DECONDECONZONEZONE

SUPPORTSUPPORTZONEZONE

Properly protected personnel only

Properly protected personnel only

EMS and othersupport personnel

EMS and othersupport personnel

Recognize Hazmat IncidentRecognize Hazmat Incident

• Scene clues: People down, dead animals Vapor cloud Fire

• Warning properties (may be unreliable): Odor Color Irritation

Protect Yourself & OthersProtect Yourself & Others

• Prevent primary exposure: Approach cautiously, upwind, uphill Isolate area and deny entry Stay out of Hot Zone

• Prevent secondary contamination: Determine risk of secondary contamination If Decon required, should be done by

properly protected personnel

Identify the Toxic Material(s)Identify the Toxic Material(s)

• DOT Guide Placards Labels

• Shipping papers

• NFPA marking system labels

• Material Safety Data Sheets (MSDS)

• On-scene chemical analysis

Determine Toxicity & HazardDetermine Toxicity & Hazard

• Regional Poison Control Centers Back-up by medical toxicologists

• CHEMTREC: 1-800-424-9300 Large file of MSDSs Contacts in key chemical industries

• Written materials Books On-line databases

Determine Toxicity & HazardDetermine Toxicity & Hazard

Specific information that may be available from the regional Poison Control Center: Toxicity/symptoms of exposure Level of protective gear required Potential for secondary contamination Decontamination required? Specific treatment

Respiratory Protective GearRespiratory Protective Gear

• Air-purifying respirators (gas masks) Do not provide oxygen Must be chemical-specific Chemical may break through

• Air-supplied respirators (SCBA) Safe air supply Limited duration of tanks

All gear must be fit-testedAll gear must be fit-tested

Chemical Protective ClothingChemical Protective Clothing

• Completely or partially encapsulating Completely encapsulated requires SCBA

• Varying resistance to chemicals Need chemical compatibility and

breakthrough data for each chemical

• Serious risk if used improperly Not flame-resistant Chemical penetration Heat stress

Chemical Protective ClothingChemical Protective Clothing

• EPA Levels A-D: A: SCBA plus encapsulating (airtight) suit B: SCBA plus partially encapsulated suit C: Air-purifying mask plus partial enc. suit D: No special gear (work clothes)

• EPA levels do not address FF gear: SCBA plus flame-resistant (not chemical-

resistant) “bunker” gear

Protective Gear in Hot ZoneProtective Gear in Hot Zone

Known or suspectedrespiratory hazard?

Known or suspectedrespiratory hazard?

Known or suspectedskin hazard?

Known or suspectedskin hazard?

No skin hazardNo skin hazard

SCBA required

Level A or B

FD turnouts ok

Heat IllnessHeat Illness

• Variables that affect body temperature: Ambient (environmental) temperature Level of physical activity State of hydration Ability to sweat evaporative cooling

• Heat stress syndromes: Heat exhaustion Heat stroke (LIFE-THREATENING!)

Heat Stress Monitoring & PreventionHeat Stress Monitoring & Prevention

• Enforced breaks Rest Force fluids Rotate work teams

• Safety officer or other designated person Monitors each person in protective gear Looks for: altered mental status, increased

pulse rate, elevated body temperature

Victim Management in Hot Zone Victim Management in Hot Zone

• Only trained and properly protected personnel may enter

• Limited activity in Level A or B gear: Open airway (with C-spine precautions) Brush off gross contaminants Carry on backboard or drag to Decon area Note: ambulatory patients may be able to

remove their own clothing and walk to Decon area

Decontamination AreaDecontamination Area

• Medical intervention still limited Access restricted to trained personnel with

protective clothing Protective gear limits ability to assess

patient, start IVs, etc

• Decontamination Determine if needed, based on victim’s Sx

and potential for secondary contamination Have victim assist, if possible

Basic DecontaminationBasic Decontamination

• Brush off/soak up gross contaminants

• Cut away or remove contaminated clothing

• Flush with copious plain water Head to toes direction 3-5 minutes (eyes: at least 5 min)

• If oily or adherent, use soap or shampoo

• Do not use “Decon Solutions”

• Collect runoff, if possible

Decontamination Decision AlgorithmDecontamination Decision Algorithm

Was exposure to gas or vapor only?

Was exposure to gas or vapor only?

Vapor condensed on clothing or skin?

Vapor condensed on clothing or skin?

Eye or skin irritation?Eye or skin irritation?

YESYES

NONO

NONO DECONTAMINATION DECONTAMINATION NOT NEEDEDNOT NEEDED

DECONTAMINATION DECONTAMINATION NOT NEEDEDNOT NEEDED

DECONTAMINATEDECONTAMINATEDECONTAMINATEDECONTAMINATEYESYES

NONO

YESYES

Support Zone ManagementSupport Zone Management

• A: Airway

• B: Breathing - give supplemental O2

• C: Circulation - start IV

• D: Decontamination - continue if needed Eyes (remove contacts) Under fingernails, armpits, etc Activated charcoal for ingestions

• S: Specific treatment if indicated

Support Zone ManagementSupport Zone Management

• Bronchospasm: Aerosolized bronchodilators Caution: possible arrhythmias

• Arrhythmias: Standard ALS procedures Exceptions: eg, Ca++ for HF

• Seizures: Usual anticonvulsants

Transport of Hazmat VictimsTransport of Hazmat Victims

• Decontaminate BEFORE transport Better for patient Less inhalation risk to ambulance personnel

• Ingested poison: Suspected corrosive: give water Give AC; do NOT induce emesis Carry extra towels and have ready some

open plastic bags to quickly isolate toxic vomitus

Hospital PreparationHospital Preparation

Develop protocols in advance, to:

• Obtain specific toxicity information Potential for secondary contamination

Expected health effects, antidotes

• Assure on-scene decon, when needed

• Designate reception & treatment areas

• Plan for the unexpected contaminated pt.

The Unexpected Contaminated VictimThe Unexpected Contaminated Victim

Indoor Facilities - Disadvantages:• Poor ventilation

Inhalation hazard from volatile vapors Surgical masks inadequate for gases or

vapors Respirators impractical

• Contaminated ED room

The Unexpected Contaminated VictimThe Unexpected Contaminated Victim

Outdoor facility preferred - equip with: Old gurney Hose with warm water, shower nozzle Soap and shampoo Disposable rubber gloves, chemical-

resistant jump suits Plastic bags for contaminated clothing Kiddie pool to catch runoff

Medical Treatment in the HospitalMedical Treatment in the Hospital

• Inhaled poisons Monitor airway, lung sounds Oxygen, bronchodilators as needed

• Skin & Eyes Complete decontamination Treat skin burns as for thermal burns Eyes: check pH, fluorescein exam

Medical Treatment in the HospitalMedical Treatment in the Hospital

• Ingested poison Have extra towels and open plastic bags to

quickly isolate and dispose of toxic vomitus If performing gastric lavage, hook up to

outside-venting wall suction Activated charcoal Corrosives: give water, consider lavage,

consider endoscopy

References/Additional ReadingReferences/Additional Reading

Burgess JL et al: Hospital preparedness for hazardous materials incidents and treatment of contaminated patients. West J Med 1997; 167:387

Kirk MA et al: Emergency department response to hazardous materials incidents. Emerg Med Clin NA 1994; 12:461

Olson KR: Hazmat-o-phobia. Why aren't hospitals ready for chemical accidents? West J Med 1998; 168:32