HZB-00/01

National Transportation Safety Board

Washington, D.C. 20594

 Hazardous Materials Incident Brief

Accident No.: DCA-99-MZ-001

Transportation Mode: Air

Type of Incident: Spill of undeclared shipment of hazardous

materials in cargo compartment of aircraft

Location: Memphis, Tennessee

Date: October 28, 1998

Carrier and Flight No.: Northwest Airlines Flight 957

Aircraft: Airbus A320

Shipper: Passenger

Container: Two plastic gallon bottles in ice chest

Injured: None

Material Released: Hydrogen peroxide, 35-percent solution

with water, an oxidizer (corrosive)

Type of Failure: Sides of bottles split

Description of Incident

On the morning of October 28, 1998, 2 gallons of a 35-percent hydrogen peroxide

solution in water, an oxidizer1 with corrosive properties, spilled in a cargo compartment of

Northwest Airlines (Northwest) flight 957, a passenger-carrying airplane en route from

Orlando, Florida, to Memphis, Tennessee. The solution leaked from two undeclared

1-gallon plastic bottles that had split. The bottles were in an ice chest that belonged to a

passenger on the flight. The leaking hydrogen peroxide contaminated three mail sacks and

an undetermined number of bags.

The leak was not discovered until cargo handlers in Memphis began to unload the

baggage on flight 957. Thinking that the spilled liquid was water, the cargo handlers

ignored it and transferred some of the baggage to other Northwest passenger-carrying

flights, including flight 7, which then departed for Seattle, Washington. When flight 7

arrived in Seattle, two bags in a cargo compartment were smoldering, including one that had

come from flight 957.

 

1

 The Department of Transportation defines an oxidizer as “a material that may, generally by yielding

oxygen, cause or enhance the combustion of other materials.”
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As a result of the spill, several people required treatment. In Memphis, 11

employees were treated at the airport’s first aid station because their hands had been

exposed to the hydrogen peroxide, and 2 more employees went to a local clinic, where they

were treated and released. In Seattle, the employee who removed the smoldering bags from

the cargo compartment was exposed to fumes. He went to a hospital for treatment and was

released. None of the injuries were serious. Northwest estimated that the total cost of the

damage to and the downtime on the aircraft and of the damage to the baggage was more

than $40,000.

Response to Contaminated Baggage

After flight 957 arrived in Memphis, two Northwest ramp employees entered the

cargo compartments, between 0730 and 0745 central standard time, and began

transferring the baggage to other aircraft in the morning bank of flights.2 Both employees

noted wet baggage and a clear liquid on the floor. They assumed the liquid was water that

had leaked from the ice chest or from a shipment of tropical fish.3

About 10 minutes after the baggage was unloaded, the employees who had

handled the wet baggage and mail sacks began to complain that their hands were tingling

and turning white. By then, some of the baggage had been transferred to other airplanes,

and some had been returned to passengers. The ice chest and several bags had been

loaded onto flight 7. (See figure 1.)

Because employees were complaining about their hands, Northwest contacted the

airport’s fire station, and it responded to the site. Northwest also contacted the airport’s post

office, which sent a postal employee to pick up the wet mail sacks. A ramp employee

retrieved the ice chest from flight 7. When he was told that the ice chest probably contained

a hazardous material, he left to seek medical attention. After he left, the pilot of flight 7

noticed that there was a cluster of emergency responders and Northwest employees near

the plane. The pilot asked them about the nature of the emergency. They told him that the

ice chest might contain a hazardous material. The pilot asked whether the ice chest had

been on flight 7. Not knowing that the chest had been on flight 7, several Northwest

employees told the pilot that it had not. Thinking that his plane was not affected by the

incident, the pilot of flight 7 departed as scheduled.

 

2

 Memphis is one of Northwest’s hub airports. Northwest has 3 daily banks of about 40 flights; the

planes are at the airport for only 1 to 2 hours.

3

 According to the ramp employees, it is common to discover ice chests leaking due to melting ice.

Also, live fish are shipped in plastic bags inside fiberboard boxes, and the bags occasionally break, spilling

the water from the box.
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The emergency responders did an on-site examination and found that each bottle

had split open and that the hydrogen peroxide had leaked from the bottles and the ice chest.

(See figure 2.) Each bottle had a label that said “Vero Chemical Distributors, Inc.,” and had

generic warnings about flammable materials. The words “Hydrogen Peroxide” were

handwritten in an upper corner of each label. When the responders questioned the passenger

who had checked the ice chest, she told them that the bottles had contained a 35-percent

solution of hydrogen peroxide.

During the emergency, the fire station responders used the North American

Emergency Response Guide and a material safety data sheet4

 about hydrogen peroxide as

references. Northwest stated that it also contacted the Minnesota Poison Control Center.5

(There is no record of the information provided by the center; however, a previous

employee indicated that, given the nature of the center, its information would have focused

on the medical hazards, including the fact that hydrogen peroxide can damage skin.) While

the information gathered described some of the hazards posed by hydrogen peroxide, much

 

4

 A material safety data sheet is developed by the producer of a chemical product and contains general

information about it, including a description of its chemical and physical properties, a description of the

health and environmental hazards it poses, and guidelines for responding to its release.

5

 At the time of the incident, the Minnesota Poison Control Center was under contract to Northwest to

provide hazardous materials information.

Figure 1. The ice chest that contained the bottles of hydrogen peroxide.
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of it did not point out that hydrogen peroxide that has dried on certain materials is a fire

hazard. A fire station responder stated that the responders were concerned about the danger

of fire from materials exposed to the oxidizing properties of hydrogen peroxide and had

warned the Northwest employees.

Northwest began telephoning Northwest management at all of the destination

airports, initially focusing on the 13 airports receiving flights that had baggage from flight

957. Callers told the management at each airport about the hydrogen peroxide spill, that

the spill had injured some Memphis ground crew employees, what first aid to use, and

that people handling the baggage should use protective gloves. Northwest recommended

that the people who unloaded the airplanes check for wet baggage and condemn and

replace any that they found. Northwest also called Northwest’s Systems Operations

Control (SOC), which telexed, to all Northwest operations offices, station managers,

maintenance managers, and control centers, information on the spill and a warning that

baggage from flight 957 might be contaminated. The SOC did not warn the pilots of the

airplanes that were carrying potentially contaminated baggage from flight 957.

Before flight 7 landed in Seattle, the Northwest employees there knew that the

plane might be carrying contaminated baggage, and the baggage handlers, as Memphis

had suggested, were protecting their hands with rubber gloves. However, no one in

Seattle had independently researched the hazards posed by hydrogen peroxide, and the

Figure 2. Damage to the bottles of hydrogen peroxide.
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Northwest telephone call from Memphis had not mentioned fire hazards. Consequently,

no one in Seattle was prepared for the possibility of a fire. The Northwest employees in

Seattle had told the local emergency responders about the Memphis spill but had not

asked any responders to stand by when flight 7 arrived in case there was a fire.

The baggage handlers reported that when they opened the cargo compartments of

flight 7, they found smoke, but no flames, coming from the area of two adjacent suitcases.

One handler said the smoke was “like someone blowing on a good cigar.” The handlers

backed away, and an equipment service employee without any protective equipment

climbed into the compartment and retrieved the smoldering suitcases. (See figure 3.)

Northwest called the fire department, which drowned the suitcases with water. A short

time later, the equipment service employee became nauseated and was taken to a local

hospital, where he was treated and released.

Northwest’s ground operations personnel are trained to react to a fire in an aircraft

by calling the fire department from a safe location and by closing exterior doors to

prevent the spread of fire inside the aircraft. Some ground operations personnel are not

trained in what actions to take when hazardous materials are spilled in cargo

compartments.

Figure 3. One of the damaged suitcases discovered in Seattle.
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Events Preceding Incident

The passenger who had checked the ice chest at Orlando was a nurse. She had

bought the hydrogen peroxide containers several years earlier and stored them unopened

at an assisted care facility for the elderly in Fort Pierce, Florida, that she had once owned.

Before her trip on flight 957, she had packed the two plastic bottles of hydrogen peroxide

in a plastic ice chest with some sand and a bag of rolls.

She arrived at the airport at 0600 eastern standard time (EST); the flight was

scheduled to depart at 0630 EST. She attempted to check seven items, including the ice

chest, at Northwest’s roadside skycap service. According to the skycap, he had been

reluctant to check the bags because Northwest allows a passenger to have only two items

checked without paying additional fees. He had told her that the fees must be paid at the

ticket counter inside the terminal, but she explained that she was late and persuaded him

to check all seven of her items. She tipped him $20 dollars and rushed off.6

The skycap said that he had asked the woman whether the ice chest contained dry

ice, a hazardous material with special limitations in air transportation. She did not declare

that there were any hazardous materials in her baggage7

 and later told investigators that

she was not aware that hydrogen peroxide was a hazardous material. She checked in with

Northwest at the gate and left Orlando on flight 957. There were no reports of incidents or

injuries at the Orlando airport involving her baggage. Northwest hazardous materials

training instructs a person accepting passenger baggage to specifically ask passengers

what is in an ice chest.

Hazardous Materials Information

According to the Hazardous Materials Regulations of the Department of

Transportation (DOT),8

 a 35-percent solution of hydrogen peroxide is an oxidizer with

corrosive properties. The proper shipping name for the product is “hydrogen peroxide,

aqueous solution with not less than 20 percent but not more than 40 percent hydrogen

peroxide.” A package containing hydrogen peroxide must be marked and labeled and have a

shipping paper that describes the material and certifies that the shipment conforms to DOT

requirements. A selection of applicable requirements that are intended to prevent or limit

spillage of hazardous materials follows:

 

6

 Northwest management indicated that the skycap was a Northwest employee and was authorized to

collect the fees for extra baggage. Northwest took disciplinary action against the skycap.

7

 A search of her other baggage in Seattle revealed other undeclared hazardous materials, including

small arms ammunition, an aerosol can of lubricant (a flammable gas), and a tube of gun oil (a combustible

liquid).

8

 Title 49 Code of Federal Regulations (CFR) Subchapter “C.”
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The maximum quantity of 20- to 40-percent hydrogen peroxide that may

be shipped aboard a passenger aircraft in a single package is one liter

(0.26 gallons).

Hydrogen peroxide must be shipped in combination packaging. Several

different forms of combination packaging are allowed for this product,

including a plastic inner packaging inside a plastic outer packaging.

However, the inner packaging must meet certain minimum requirements to

prevent leakage, and the outer packaging must be manufactured, tested,

and marked to DOT packaging specifications (see 49 CFR 173.202).

When transported by aircraft, the plastic inner packaging must be enclosed

by a tightly closed metal receptacle before it is placed in the outer

packaging.

Closures on the inner packaging must be upright, and opposite sides of the

outer packaging must have arrows indicating the correct upright direction.

Vero Chemical Distributors, Inc., the company that labeled the gallon bottles of

hydrogen peroxide, said that it sells its product only to local customers and does not

prepare or package the product to be transported in accordance with the Hazardous

Materials Regulations.

Fire Hazard—Hydrogen peroxide is a very powerful oxidizing agent that can

oxidize all organic compounds and a wide range of inorganic ones. It is not flammable, but

it can readily cause other materials to burn. Natural materials like wood, paper, cotton, and

leather are very susceptible to fire when exposed to hydrogen peroxide. These reactions are

enhanced when the material contains dirt, especially metallic compounds of copper, silver,

or mild steel.9

Hydrogen peroxide is generally shipped in solution with water. Solutions range from

those used as an antiseptic (2 to 3 percent), through industrial strengths (27.5 to 70 percent),

to concentrations used in specialized industry, military, and rocket propulsion (86 to 100

percent). The more concentrated the solution, the more reactive it is.

If a hydrogen peroxide solution is allowed to evaporate, the water evaporates more

quickly than the hydrogen peroxide does, causing the solution to become more

concentrated. As a hydrogen peroxide solution becomes more concentrated and is exposed

to organic materials and dirt or metallic compounds, the hydrogen peroxide begins to

 

9

 Mild steel is a carbon steel with a maximum of about 0.25 percent carbon.
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decompose. This decomposition results in an exothermic reaction10 and the release of

oxygen, which will support combustion.

On February 3, 1988, American Airlines flight 132, a McDonnell Douglas DC-9-

83, had an in-flight fire while en route to Tennessee from Texas.11 The fire eventually

breached the cargo compartment, and the passenger cabin floor over the middle cargo

compartment was charred. The investigation determined that the fire had been caused by

an undeclared and improperly packaged shipment of hydrogen peroxide. Further,

according to the incident data base of the Research and Special Programs Administration,

from 1995 through 1999, there were nine incidents involving hydrogen peroxide in air

transportation.

Material Safety Information—Safety Board investigators reviewed several

material safety data sheets about hydrogen peroxide, including those provided by

Northwest. Most of the sheets warned that people who handle hydrogen peroxide

solutions need protective clothing and that contaminated clothing should be laundered

before being reused. The sheets, however, did not explain the reasons for the warnings,

and only about half of the sheets warned that allowing the product to dry on clothing or

combustible materials may cause a fire.

Handling of Mail

The post office employee who picked up the wet mail sacks called a post office

safety officer in the central Memphis post office to report that the mail sacks were

contaminated with a liquid. The safety officer told him to isolate the mail sacks on the

docks until he, the safety officer, arrived. By the time he arrived, the contamination had

been identified as hydrogen peroxide. He then said that the mail should be dumped from

the nylon sacks into large open wire bins and allowed to dry outside. That evening, after

the mail had dried outside, it was shipped by ground transportation to its destination,

Kansas City, Missouri. The safety officer said that he was familiar with hydrogen

peroxide and did not refer to any specific information on the hazards or properties of the

chemical in determining the actions to be taken.12 The Postal Service did not have any

subsequent incidents involving the contaminated mail.

 

10 A chemical reaction that results in the generation and release of heat.

11 National Transportation Safety Board. 1988. In-flight Fire, McDonnell Douglas DC-9-83, N569AA,

Nashville Metropolitan Airport, Nashville, Tennessee, February 3, 1988, Hazardous Materials Incident

Report NTSB/HZM-88/02. Washington, D.C.

12 Postal Service training material about hazardous materials emergency response states that postal

employees responding to a hazardous materials spill should determine the hazards of the material by using

material data safety sheets and other information.
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Postincident Actions

The Federal Aviation Administration has initiated action against the passenger for

violating the Hazardous Materials Regulations.

Probable Cause

The National Transportation Safety Board determines that the probable cause of

the release of undeclared hazardous material aboard Northwest Airlines flight 957 was

the passenger’s failure to properly package and identify the hazardous material and

inadequate inquiries from the Northwest Airlines agent about the contents of the cooler

offered by the passenger. Contributing to the consequences of the release were inadequate

carrier procedures, which allowed contaminated baggage to be transferred to other

aircraft.

Recommendations

As a result of this accident, the National Transportation Safety Board makes the

following safety recommendations:

to the Federal Aviation Administration:

Develop, with the assistance of the Hydrogen Peroxide Safety

Producers Committee, and distribute to carriers guidance about the

difficulty of identifying a hydrogen peroxide spill and about the danger

of allowing hydrogen peroxide to dry on organic materials (including

paper, fabric, cotton, and leather), which may result in a fire. (A-00-51)

Issue guidance to air carriers about the need to isolate baggage and

cargo that have been involved with a hazardous materials spill until it

can be determined which items have been contaminated and what

measures are necessary to prevent further contamination of baggage

and aircraft or other hazards (such as fire or poisoning). Then require

principal operations inspectors to review and amend, as necessary, air

carrier manuals to ensure that air carrier procedures are consistent with

this guidance. (A-00-52)

Issue guidance to air carriers about the need to notify pilots in flight

when baggage and cargo that are believed to have been involved in a

hazardous materials spill have been placed on their aircraft; notifying

the pilots includes clearly identifying the hazards posed by the material
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involved in the spill and the procedures that the pilots should take.

Then require principal operations inspectors to review and amend, as

necessary, air carrier manuals to ensure that air carrier procedures are

consistent with this guidance. (A-00-53)

to the U.S. Postal Service:

Reinforce the training provided to your hazardous materials emergency

responders concerning the need to use technical information, including

material safety data sheets, about the hazards and the chemical

properties of materials when responding to a spill instead of relying

solely on memory or previous experience.(A-00-54)

to the Air Transport Association:

Inform your members about the Memphis incident and make them

aware of the following: the difficulty of identifying a hydrogen

peroxide spill, the danger of allowing hydrogen peroxide to dry on

organic materials, the need to isolate baggage and cargo that have been

involved with a hazardous materials spill until it can be determined

which items have been contaminated and what measures are necessary

to prevent further contamination of baggage and aircraft or other

hazards (such as fire or poisoning), and the need to notify pilots in

flight when baggage and cargo that are believed to have been involved

in a hazardous materials spill have been placed on their aircraft (such

notification includes informing the pilots clearly about the hazards

presented by the material involved in the spill and the procedures that

the pilots should take). (A-00-55)

to Northwest Airlines, Inc.:

Amend your emergency response procedures and training to include

the importance of isolating baggage and other cargo that has been

involved with a hazardous materials spill until it can be determined

which items have been contaminated and what measures are necessary

to prevent further contamination of baggage and aircraft or other

hazards (such as fire or poisoning). (A-00-56)

Amend your emergency response procedures and training to include

notification to pilots in flight when baggage and cargo that are believed

to have been involved in a hazardous materials spill have been placed

on their aircraft; notifying the pilots includes clearly identifying the
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hazards posed by the material involved in the spill and the procedures

that the pilots should take. (A-00-57)

Reinforce the training provided to ground operations and maintenance

personnel on actions to take for a suspected fire in an aircraft cargo

compartment. Also for those employees, review and modify, as

appropriate, procedures and training for a suspected hazardous

materials spill in an aircraft cargo compartment. (A-00-58)

to the Hydrogen Peroxide Safety Producers Committee:

Urge your members to revise their material data safety sheets for

hydrogen peroxide to include warnings about the dangers of allowing

hydrogen peroxide to dry on organic materials (including paper, fabric,

cotton, and leather), which may result in a fire. (A-00-59)

Assist the Federal Aviation Administration in developing guidance for

air carriers about the difficulty of identifying a hydrogen peroxide spill

and about its hazards. Include, at a minimum, the fact that hydrogen

peroxide is colorless, has little odor, and may be mistaken for water;

the guidance should also warn of the danger of allowing hydrogen

peroxide to dry on organic materials (including paper, fabric, cotton,

and leather), which may result in a fire. (A-00-60)

Adopted May 17, 2000