Whatman Filter Paper - Grade 4 Circles
These cellulose filters are used in qualitative analytical techniques to determine and identify materials. Prepleated qualitative filters are also available, which give improved flow rate and increased loading capacity compared to equivalent flat filters.
Grade 4 (20-25 µm)
Extremely fast filtering with excellent retention of coarse particles and gelatinous precipitates such as ferric hydroxide and aluminum hydroxide. Very useful as a rapid filter for routine clean-up of biological fluids or organic extracts during analysis. Used when high flow rates in air pollution monitoring are required and the collection of fine particles is not critical.


Available In The Following Sizes
Diameter P/Box
42.5 mm 100
55 mm 100
70 mm 100
90 mm 100
110 mm 100
125 mm 100
150 mm 100
185 mm 100
240 mm 100
270 mm 100
320 mm 100


Due to the continuous development of our products, the goods supplied may vary in detail to that illustrated on our website.