First Aid for Accidental Needle Pricks

Read this before you prick yourself!

Emulsions containing Complete Freund's Adjuvant (CFA)

Needle pricks with CFA emulsions cause inflammation at the puncture site due to immune response against heat-killed M. tuberculosis. The response is stronger in people vaccinated against tuberculosis (BCG vaccine, routine outside of the USA).

Keep alcohol and sterile 16 gauge needles handy when administering CFA emulsions.

Time is of the essence. In case of accidental prick, IMMEDIATELY:

  1. Remove glove/garments.
  2. Wipe the site with alcohol.
  3. Cut/widen the puncture site to increase bleeding from the penetrated area.
    • Use a sterile 16 or 18 gauge needle if available
    • Puncture the prick site 3 or 4 times
    • Try to have another person do it; they may be able to puncture deeper
  4. Continually squeeze blood from the wound under warm tap water (this keeps the blood flow going) for 5 minutes.

This greatly reduces the chance of an immune reaction. It must be done IMMEDIATELY after the prick – doing it an hour later is not very useful.

If done promptly, this will usually prevent inflammation development at the site.

If inflammation does develop, it appears as a nodule at the site of the prick. This inflammation usually disappears within a few months. In rare cases, surgical removal of the nodule may be needed.

IFA emulsions, pertussis toxin (PTX) solutions

The procedure above is not necessary for these pricks. IFA or solutions of PTX cause at worst minor inflammation which disappears within a few days.

PTX is a component of the DTaP (Diphtheria, Tetanus, acellular Pertussis) vaccine routinely administered to infants. Any accidental prick would inject orders of magnitude less PTX than normal vaccination.


Hooke products are for research use only and are not intended for human use.

This is first aid; not medical advice. It is based on our experience handling these products. Consult a medical professional with any concerns.

Version: 2023-04-23