Whatman 1004-185 Filter Circles, 185mm Dia, Grade 4, 100/pk (PN:1004-185)

Grade 4 filter papers are designed for routine qualitative filtration, especially when separating coarse particles and gelatinous precipitates from liquids. They are commonly used in environmental testing, food analysis, and general laboratory sample preparation.

Grade 4 is known for its very fast flow rate and coarse particle retention (20–25 µm). This makes it ideal for applications where speed is more important than capturing very fine particles, unlike finer grades such as Grade 1 or 2.

This filter is best suited for samples with larger particulates, including soil suspensions, precipitates like ferric hydroxide, biological fluids, and organic extracts. It performs well when quick clarification is needed without clogging.

This product features a 185 mm diameter, cellulose construction, and particle retention of approximately 20–25 µm. It is supplied in packs of 100 filters and offers fast filtration with consistent performance.

Cellulose filter paper provides a clean, hydrophilic surface with low extractables and minimal fiber shedding, ensuring reliable results. Grade 4 specifically offers a balance of durability, speed, and sufficient retention for everyday lab workflows.