40 CFR §420.21

1. (a)For the sintering subcategory, the term product means sinter agglomerated from iron-bearing materials.
2. (b)The term dry air pollution control system means an emission control system that utilizes filters to remove iron-bearing particles (fines) from blast furnace or sintering off-gases.
3. (c)The term minimum level (ML) means the level at which the analytical system gives recognizable signals and an acceptable calibration point. For 2,3,7,8-tetrachlorodibenzofuran, the minimum level is 10 pg/L per EPA Method 1613B for water and wastewater samples.
4. (d)The term pg/L means picograms per liter (ppt = 1.0 × 10-12 gm/L).
5. (e)The term sintering means a process for agglomerating iron-bearing materials into small pellets (sinter) that can be charged to a blast furnace.
6. (f)The term wet air pollution control system means an emission control system that utilizes water to clean process or furnace off-gases.