I checked the Natural Medicines Comprehensive Database and found out this information:
Candlenut is also known as Candleberry, Tung Seed and Balucanat.
The oil from this seed is used in soaps, linoleum, and in wood preservation and varnish (for example tung oil)
It is likely UNSAFE when used orally. This seed is believed to contan the toxins toxalbumin and hydrogen cyanide. The toxicity level ranges from servere stomach pain and irritation to death. Even a single seed might cause severe poisoning. The seed also has a laxative effect. Candlenut can promote excessive sweating, stomach pain, violent vomiting, diarrhea, slowed reflexes, slowed breathing and possible death. Skin contact can cause dermatitis.
Hope this information helps
SP Registered Dietitian Becky