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Suspicious Packages, Letters or Substances


Screening Packages and Letters

Biological or chemical threats targeting individuals or departments can be controlled by screening incoming materials and by following the procedures listed below. Caltech has plans in place to deal with these types of threats. Following the procedures below will activate those plans and promote the highest level of safety while minimizing the disruption associated with these incidents. Some common features of suspect letters/packages are:

  • liquid leaking from package
  • no return address
  • hand-written or poorly typed address
  • misspelling of common words
  • restrictive markings such as "Confidential", "Personal", etc.
  • excessive weight and/or feel of a powdery or foreign substance
  • foreign post marks and/or writing
  • source of the letter/package is not recognized by recipient/addressee

If you receive a letter or note threatening biological contamination (i.e., Anthrax) or other suspect substances:

  1. Remain calm. Although any threatened use of a biological agent must be treated as though it is real, experience has demonstrated that these are likely to be a hoax. If the suspected biological agent is reported as anthrax, be assured that it is NOT generally contagious (i.e., spread from person to person) and that treatment is available and effective if administered before the onset of symptoms.
  2. Do not open the letter or package.
  3. Contact Security at x5000 or (626) 395-5000.
  4. Remain at the site until Security arrives with instructions.

If you inadvertently open a package or letter, or if it is leaking:

  1. Immediately set the item down gently at the location where it was opened.
  2. Contact Security at x5000 or (626) 395-5000.
  3. All potentially exposed persons should wash exposed skin surfaces with soap and water.
  4. Return to an area within the building adjacent to the initial exposure and wait for security (for example hallway outside original room).
  5. Do not allow others into the area. if anyone enters the area, they should stay in the area until instructed to leave by university police or other public safety responders.

What you should NOT do:

  1. DO NOT pass the letter or package to others to look at.
  2. DO NOT disturb any contents in the letter or package. Handling the letter or package may only spread the substance inside and increase the chances of it getting into the air.
  3. DO NOT ignore the threat; it must be treated as real until properly evaluated.
  4. DO NOT leave the building until instructed to do so.

For instructions from the United States Postal Office on handling suspicious letters and parcels, go to