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The views in this presentation are those of the U. S. Consumer Product Safety Commission (CPSC) The views in this presentation are those of the U. S. Consumer Product Safety Commission (CPSC) staff and they have not been reviewed or approved by, and may not necessarily reflect the views of, staff and they have not been reviewed or approved by, and may not necessarily reflect the views of,

the Commission.the Commission.

Dr. Christopher J. MustoDr. Christopher J. MustoChemistry Division—Laboratory SciencesChemistry Division—Laboratory Sciences

Alternative Testing Methods for Alternative Testing Methods for Aerial Shells in Consumer FireworksAerial Shells in Consumer Fireworks

andandAdult SnappersAdult Snappers

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• U.S. CPSC Fireworks Standards Development• Review of AFSL’s Black Powder Equivalency Test• Measuring Dynamic Pressure

• Equipment• Software• Expertise• Results • Adult Snappers

Bethesda, MD Rockville, MD

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• In 2006, the CPSC put forth an advance notice of proposed rulemaking (ANPR) to amend the regulations for certain fireworks devices.

• Since 2011, CPSC staff has been considering possible alternatives to improve or clarify current regulations.

• In 2012, a new approach to assess blast overpressure of “whole-shell” aerial devices was evaluated.

• http://www.cpsc.gov/PageFiles/138398/Fireworks-Status-2013.pdf

• Staff continues to explore easy yet effective testing alternatives.

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• Bans fireworks intended to produce audible effects … if the audible effect is produced by a charge of more than 2 grains of pyrotechnic composition.

• When the rule was written, consumer fireworks were typically made with a black powder expelling charge and flash powder in paper reports inside the shell.

• In implementing the rule, it has been assumed that the sound of a report was a surrogate for its explosive power.

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Consumer Firecracker

Consumer Aerial Device

Professional Aerial Device

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Staff initiatives:

• determine the potential risks associated with aerial devices due to blast overpressure

• coordinate with experts in the field

• develop a test to objectively determine overload limits • ensure test methods are effective and safe

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• Total pressure versus static pressure – different measuring techniques

• Magnitudes slightly different, but similar behavior

• Short rise time leads to strong pressure front

• Pressure wave velocity affects damage

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• Dynamic Pressure Sensor Range: 0 – 500 psi

• Pressure Sensor Distance to Shell: 5.5 inches to center

• Data Acquisition Rate: 50,000 acquisitions per second

• Pressure Sensor Sensitivity: 10 millivolts per psi (1 volt = 100 psi)

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Dynamic Pressure Transducer

Effects ContainmentCage

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3 grams of flash powder (5.5 inches from sensors)

Average: 142 psiPeak: 167 psi

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• Large shells produce explosions with pressure waves that are similar to an M-80 at close range.

• Large shells are designed to function 100+ feet in the air, reducing risk of injury.

• The AFSL test can distinguish the power of black powder versus hybrid powder versus flash powder, but it does not consider how much powder is present in the shell.

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Pressure, psi

Fused Firecracker (1 inch)

Pressure: ~ 6.5 psi

-7.50

7.50

5.00

2.50

-5.00

-2.50

Pressure, psi

Adult Snapper (0.7 inch)

Pressure: ~ 0.88 psi

-0.50

1.00

0.75

0.50

-0.25

0.25

Adult snappers typically have 1/8 the energy of consumer firecrackers.

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• Experiments show the pressure associated with adult snappers is about 14% of the pressure from legal firecrackers.

• 16 CFR §1500.17(a)(8) limits firecracker-type devices intended to produce an audible report to 50 mg of pyrotechnic material.

• Devices, including adult snappers, are subject to FHSA labeling: “Use only under [close] adult supervision”.

• There is no evidence of mass detonation associated with boxes of 20 or cartons of 600 devices, when they are dropped from a height of up to 8 feet.

www.cpsc.gov www.SaferProducts.gov (REGISTER) www.recalls.gov Recall Handbook (pdf) (Revised March 2012) Christopher Musto– 301-987-2090 CMusto@cpsc.gov