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Safe Harbor® Testing & Standards
Safe Harbor® standards identify the maximum level of mercury concentration allowed in each species of fish sold with the Safe Harbor® seal. Safe Harbor® certification standards vary by species since each species contains different average levels of mercury. Our standards are reported in parts per million (ppm), which is how the government measures the mercury concentration in fish. The FDA action level for mercury in all seafood is 1.0 ppm.
Certain species of fish such as swordfish, shark and king mackerel are known to be higher in mercury on average, while some other types of fish are known to be generally lower in mercury. The Safe Harbor® certification does not mean that fish known to be higher in mercury are safe for pregnant women, women who may become pregnant, nursing mothers, and small children. The FDA and U.S. Environmental Protection Agency (EPA) advise these groups not to eat any amount of swordfish, shark, king mackerel and tilefish, and to eat up to only 12 ounces per week of fish that are lower in mercury. For more information about mercury in fish, consult your physician or the following federal government website: www.epa.gov/ost/fish.
These charts identify Safe Harbor® testing methodology and mercury certification standards for each species of fish and shellfish we test. There are two ways Safe Harbor® tests fish: testing each individual fish and batch testing.
Individual Testing
Safe Harbor® tests the following fish individually and certifies that each will not exceed the maximum mercury concentration level identified for each species:
| Species | Safe Harbor® mercury standard (ppm) | Species | Safe Harbor® mercury standard (ppm) |
| Bass, Black | 0.5 | Mahi-Mahi | 0.4 |
| Bass, Bluenose Sea | 0.3 | Ono (Wahoo) | 0.4 |
| Bass, Chilean Sea | 0.3 | Opah | 0.7 |
| Bass, White California Sea | 0.3 | Sablefish (Black Cod) | 0.5 |
| Bass, Wild Striped | 0.5 | Salmon, King | 0.2 |
| Corvina | 0.3 | Shark, Thresher | 0.8 |
| Escolar | 0.5 | Snapper, Thai | 0.4 |
| Grouper | 0.5 | Swordfish | 0.8 |
| Halibut | 0.5 | Tuna, Albacore (Tombo) | 0.4 |
| Lingcod | 0.4 | Tuna, Yellowfin (Ahi) | 0.4 |
| Marlin | 0.8 | Whitefish | 0.2 |
| Monkfish | 0.2 | Yellowtail (Hamachi) | 0.4 |
Batch Testing
Safe Harbor® tests the following fish using a batch testing method based on an industry-standard sampling algorithm. This method is typically used on low-mercury fish and provides at least a 95 percent probability that tested fish will be below the mercury concentration level identified for that species:
| Species | Safe Harbor® mercury standard (ppm) | Species | Safe Harbor® mercury standard (ppm) |
| Arctic Char | 0.2 | Salmon, Coho | 0.1 |
| Barramundi | 0.1 | Salmon, Sockeye | 0.1 |
| Basa (Swai) | 0.1 | Scallops | 0.1 |
| Catfish | 0.1 | Shrimp | 0.1 |
| Cod (Alaska Cod) | 0.2 | Snapper, Red | 0.4 |
| Cod (True Cod) | 0.2 | Sole, Dover | 0.3 |
| Crab | 0.2 | Sole, English | 0.2 |
| Dory, John | 0.3 | Sole, Petrale | 0.2 |
| Eel | 0.3 | Sole, Rex | 0.3 |
| Lobster | 0.1 | Squid | 0.1 |
| Mussels | 0.1 | Steelhead | 0.1 |
| Opakapaka | 0.2 | Tilapia | 0.1 |
| Prawns | 0.1 | Trout | 0.1 |
| Rockfish | 0.2 | Whitefish | 0.2 |
| Salmon, Atlantic | 0.1 |
Understanding Tested Mercury Levels in Seafood
Mercury levels in seafood are commonly reported as mercury concentration, measured in parts per million (ppm). Micro Analytical Systems, Inc. (MASI) tests all Safe Harbor Seafood® at processing facilities before it is delivered to retailers and restaurants. The mercury level that MASI measures is based on the mercury concentration in the fish at the time the test is performed. However, seafood typically loses some moisture between the time the fish leaves the processing facility and when it is consumed. This moisture loss may cause the mercury in the fish to become more concentrated. So although the total amount of mercury in any given fish does not change over time, later testing of the fish may show a higher concentration due to moisture loss.
How We Test Fish For Mercury
To test fish and seafood for mercury, MASI has developed a mercury analyzer that uses advanced technology to precisely measure the amount of mercury in fish. An operator in the processing plant takes a small sample from a piece of fish and inserts it into the testing unit, which quickly analyzes it for mercury content. Fish that meet Safe Harbor® standards [link to testing and standards] are labeled with the Safe Harbor seal and distributed to grocery stores and restaurants.
In order to ensure accuracy, the MASI mercury analyzer is regularly calibrated using reference materials checked against standards set by the National Institute of Standards and Technology. MASI tests more seafood for mercury each year than any other company or government agency in the world.