How to Identify a Bomb

Letter and package bombs can be very dangerous and destructive. However, unlike a bomb that goes off suddenly and with no warning, they can be identified. High-risk search teams keep the following phrase in mind at all times: Look for the presence of the unusual or the absence of the usual. Observe the following procedures and warning signs.



1. Examine unexpected parcels or letters.

If a carrier delivers an unexpected bulky letter or parcel, inspect it for lumps, bulges, or protrusions, without applying pressure. Check for unevenly balanced parcels.

2. Note any unusual labeling.

Handwritten addresses or labels from companies are unusual. Check to see if the company exists and if they sent a package or letter.

3. Be suspicious of packages wrapped in string.

Modern packaging materials have eliminated the need for twine or string.

4. Beware of excessive postage.

Watch out for excess postage on small packages or letters—this indicates that the object was not weighed by the post office. It is no longer legal to mail stamped parcels weighing more than 16 ounces at mailboxes in the United States—they must be taken to a post office.

4. Beware of leaks, stains, protruding wires, or excessive tape.

Be especially wary of oil stains.

5. Beware of articles with no return address or a nonsensical return address.


Government agencies use well-defined search procedures for bombs and explosive devices. After a bomb threat, the following can be used as a guide for searching a room, using a two-person search team.

1. Divide the area and select a search height.

The first searching sweep should cover all items resting on the  floor up to the height of furniture; subsequent sweeps should move up from there.

2. Start back-to-back and work around the room.

Face in opposite directions, moving toward each other.

3. Begin searching around the walls.

Proceed inward in concentric circles toward the center of the room.

4. If you find a suspicious parcel or device, do not touch it.

Call emergency services or the bomb squad.


There are several types of devices and methods that can be used to identify bombs, including metal and vapor detectors, as well as X-ray machines. Several devices are portable and inexpensive enough for an individual to obtain.

Particulate Explosives Detector

  • Detects modern plastic explosive constituents as well as TNT and nitroglycerin.

  • Detects RDX (used in C4, PE4, SX2, Semtex, Demex, and Detasheet), PETN (used in certain military explosives and Semtex), TNT (trinitrotoluene), and NG (nitroglycerin).

  • Uses IMS (ion mobility spectroscopy) to detect micron- size particles used in explosives. A sample size of one nanogram is sufficient for detection.

  • To use, swipe the suspect material with a sample wipe or a cotton glove. Analysis time is approximately three seconds. A visual display contains a red warning light and an LCD, giving a graphic display with a relative numerical scale of the target materials identified. An audible alarm can be triggered based on a user-defined threshold.

  • Requires AC or a battery.

  • Approximately 15 x 12 x 5 inches.

Portable X-Ray System

  • Uses a digital image processor to create detailed images of parcels and packages.

  • Requires AC or a rechargeable battery.

  • To use, simply point the x-ray generator at the suspect item and view the digital image.

Bomb-Detection Dog

  • Specially trained canines are able to detect various types of explosives using their highly-attuned sense of smell.

  • Walk the dog through the security line at the airport and allow it to sniff carry-on bags.


All bomb experts stress that avoidance is the key concept when dealing with explosives. Your best chance of survival lies with the bomb squad, not with one of these devices.