Grapefruits with TBZ

While strolling around fruit stands in Japanese supermarkets I noticed sign in Japanese that says that grapefruit is covered with TBZ. As later I found out, Japan has a labeling rule (Source: USDA) that if fruit is covered with TBZ or other post harvesting fungicide, it has to be properly labeled. In Japan, post harvest fungicides (PHF) are classified as food additives (because PHF’s serve as food preservative). This labeling rule is applied to all exporters to Japan. However, I am not sure if it also applies to local producers.

What is TBZ? Well, according to US Environmental Protection Agency (EPA) report published in 2002 (Source: EPA) thiabendazole (TBZ) is a pesticide that is used to control a variety of fruit and vegetable diseases such as mold, blight, rot and stains caused by various fungi.”

It looks like not only citrus fruits can have TBZ residues, but also other fruits can be covered with this fungicide, including apples, pears and other fruits and greens (Source: What’s on my food).

In Japan following products are allowed to be treated with PHF’s, namely, apples, apricots, bananas, cherries, citrus fruits, Japanese plums, kiwifruits, loquats, nectarines, peaches, pears, pomegranates, and quinces (Source: USDA).

Japan allows following PHF’s:

• Diphenyl
• Imazalil
• Phenylphenol (OPP)
• Sodium
• Phenylphenate (OPP)
• Tiabendazole (TBZ)
• Fludioxonil

Few examples of labeling PHF’s in Japan:

Actually TBZ is also used in drug industry for control of parasitic infestations in humans.

Main health concerns:

• TBZ mainly impact thyroid and liver function (Source: EPA).
• Likely to be carcinogenic (Source: EPA).
• Dizziness, Nausea, Vomiting, Anorexia (Source: INCHEM).
• Rarer: abdominal pain, headache, drowsiness, weariness, heartburn, diarrhea or constipation, flatulence, blurring of vision, xanthopsia, skin eruption, malodorous urine. (Source: INCHEM)

How to determine if fruit is covered with TBZ, even if it’s not labeled? Well good chance is if the fruit is waxed, it usually has some type of PHF added. If you take citrus in your hand and your hand is covered with small shiny residues, my guess is you just came in contact with some type of PHF.

Otherwise, let’s hope also other countries apply such labeling system.

More info:

EXTOXNET: Extension Toxicology Network: Thiabendazole
Toxicological evaluation of certain veterinary drug residues in food: TIABENDAZOLE