Down testing is best performed after the down is washed and dried but before it is used in the final products. This allows tighter control over products all the way through final production. There are several industry accepted tests for feather and down fill used in bedding and other finished products. The three most prominent tests are listed below.
Fill power is a measurement of how ‘fluffy’ or lofty down is. This test involves filling a cylinder tube with 30 grams of down and measuring how many cubic inches of space it takes up. A specially calibrated weight is placed on top of the down and is allowed to slowly fall for 60 seconds. The test is done three times and an average is taken of the three tests for a final result. The higher the fill power, the loftier the down is and the better an insulator it is. Typical fill power is approximately 550-600 cubic inches and can reach as high as 800 or more in premium bedding. As fill power increases, so does the price of the down. View the video to see this test in action.
Turbidity is a test that involves adding 10 grams of down into 1 liter of water. This container of down and water is sealed and vigorously shaken for 30 minutes. The mixture is then strained into a graduated cylinder. The tester will look down into the opening of this cylinder to see if a pair of crosshairs on the bottom are visible. The cylinder is filled to the top marker. If the tester has trouble viewing the crosshair the cylinder is slowly emptied until it is visible from the top. The marking where the water is equals the cleanliness of the down. The minimum standard in the United States is 300mm, and 500mm is considered “hypo-allergenic”. The higher the turbidity number, the ‘cleaner’ the down. View the video to see this test in action.
The oxygen test further proves the cleanliness of the down, where organic materials are measured. Organic materials are dirt and bacteria from the down. The test adds specially measured chemicals to the same water used for the turbidity test. The lower the oxygen count, the less organic materials that are present in the finished product. A good oxygen test measures 4.5 or lower. The standard in the United States is a maximum of 10 (mg/100g) and 4.8 or less is considered “hypo-allergenic”.
There are many labs for the testing of down products. Two common labs are: International Down and Feather Laboratories (IDFL) and California Down & Feather Testing Laboratory (CDFTL). Both facilities regularly test down from both down processors and retailers of the finished goods. Many larger retail and catalog chains request officially certified tests from these companies to audit their inventory of down product.