Whatman 1004-150 Filter Circles, 150mm Dia, Grade 4, 100/pk (PN:1004-150)

Whatman Grade 4 filter circles are qualitative cellulose filters designed for routine lab filtration tasks. They are especially suited for applications requiring fast flow rates and effective trapping of larger particles and gelatinous precipitates, such as clarifying biological fluids or organic extracts.

This filter has a nominal particle retention range of 20–25 µm, which makes it effective at capturing coarse particles and precipitates while allowing liquids to pass through quickly.

This product contains 100 circular filter papers, each with a 150 mm diameter, making them suitable for larger funnels and filtration setups typical in environmental, research, and quality-control labs.

Grade 4 filter paper is known for its high flow rate, excellent retention of coarse particulates and gelatinous materials like ferric hydroxide, and low ash content (≤ 0.06 %), which helps reduce background residue in qualitative analyses.

These filters are ideal for qualitative analytical separations where speed is important and very fine particles are not the focus. Typical uses include routine sample cleanup, environmental air monitoring collection, and general lab filtration tasks that do not require ultra-fine retention.