What is the maximum safe cold-holding temperature for histamine-producing fish?

• A. Below 32°F
• B. Below 28°F
• C. Below 40°F
• D. Below 42°F

Answer: (C)

Controlling cold holding temperature is essential to prevent histamine formation in fish that can produce histamine. Some fish, like tuna and mackerel, can develop histamine quickly when stored at warmer temperatures because bacteria convert histidine in the fish into histamine. To prevent this, the safe practice is to keep cold-holding temperatures at 40°F (4°C) or below. This is the maximum temperature that still slows or stops the histamine-forming bacteria, reducing the risk of histamine poisoning.

Choosing a temperature below 40°F ensures safety, while temperatures above 40°F would allow histamine to form. Extremely cold temperatures (well below freezing) might affect texture but aren’t the reason for the safety limit. A choice that allows storage up to 41°F, for example, would not meet the safety requirement, since histamine risk increases once you exceed 40°F.