Chemicala and Heat Inactivation of Toxins

Toxin2.5% NaOCI + 0.25N NaOH2.5% NaOCI1% NaOCIAutoclaving
T-2 mycotoxinYesNoNoNo
BrevetoxinYesYesNoNo
MicrocystinYesYesYesNo
TetrodotoxinYesYesYesNo
SaxitoxinYesYesYesNo
PalytoxinYesYesYesYes
RicinYesYesYesYes
BotulinumYesYesYesYes
Staphylococcal enterotoxinYesbYesbYesbYesb

 a = 30 minute exposure to various concentrations of sodium hypochlorite with or without sodium hydroxide.
 b = assumed inactivation

Conotoxin

Conotoxin inactivation depends on the presence or absence of disulfide bonds.

  • For conotoxins with disulfide bonds, incubate with an excess of dithiothreitol (DTT) (usually 10-20mM buffered solution, pH8.7) for at least 1 hour at room temperature or 30 minutes at 50oC.  Add an equal volume of 50-100mM solution of iodoacetamide (buffered solution, pH8.7) and incubate for 1 hour at room temperature.
  • For conotoxins without disulfide bonds, incubate in a closed glass vial with 6N HCl for 24 hours at 90-110oC. 

For skin contact, use soap and water to remove toxin burden.  Mycotoxins are dermally active; however, washing even 1 hour after contact with T-2 can prevent dermal toxicity. 

Recommendations:

  • For complete inactivation of T-2 mycotoxin and brevetoxin, all liquid samples, accidental spills, nonburnable waste, and cages and bedding from animals exposed to these toxins, soak in 2.5% NaOCl + 2.25%N NaOH for 4 hours.
  • All burnable waste from toxins should be incinerated at temperatures in excess of 1500oF (815oC).