| Feature | Typical Particle Retention in Liquid | Description |
| Grade 1 | 11 µm | A widely used standard grade filter paper for routine applications with medium retention and flow rate. It covers a wide range of laboratory applications and is frequently used for clarifying liquids. |
| Grade 2 | 8 µm | Slightly more retentive than Grade 1 with a corresponding increase in filtration time (i.e., slightly slower filtration speed). More absorbent than Grade 1. In addition to general filtration in the 8 µm particle size range, the extra absorbency is utilized, for example, to hold soil nutrient in plant growth trials. |
| Grade 3 | 6 µm | Double the thickness of Grade 1 with still finer particle retention and excellent loading capacity; more precipitate can be held without clogging. The extra thickness gives increased wet strength and makes this grade highly suitable for use in Büchner funnels. The high absorbency is particularly valuable when the paper is used as a sample carrier. |
| Grade 4 | 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. |
| Grade 5 | 2.5 µm | The maximum degree of fine particle filtration in the qualitative range. Capable of retaining the fine precipitates encountered in chemical analysis. Slow flow rate. Excellent clarifying filter for cloudy suspensions and for water and soil analysis. |
| Grade 6 | 3 µm | A standard grade filter for boiler water analysis. 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. Twice as fast as Grade 5 with similar fine particle retention. Often specified for boiler water analysis applications. |
| Grade 597 | 4-7 µm | A medium fast filter paper with medium to fine particle retention. Used for a wide variety of analytical routine applications in different industries like food testing (e.g., determination of fat content) or removal of carbon dioxide and turbidity from beverages (e.g., beer analysis). |
| Grade 602 h | < 2 µm | A dense filter paper for collecting very small particles and removing fine precipitates. Used in sample preparation (e.g., in the beverage industry for residual sugar determination, acidic spectra, refractometric analysis, and HPLC). |
| Grade 602 h.5 | < 2 µm | Folded Prepleated. Used in sample preparation (e.g., in the beverage industry for residual sugar determination, acidic spectra, refractometric analysis, and HPLC). |
| Grade 2555.5 | 12 µm | Folded Prepleated. A medium fast filter paper used for the filtration of the mash for the determination of the extract in malt and wort and for removing carbon dioxide from beer. |
| Grade 0858.5 | 12 µm | Folded Prepleated. Grained, with medium fast flow rate and medium retention. A universal filter paper, used for the filtration of extracts, oils, beer, syrups, etc.; also applied in filter presses or for the aspiration of liquids. |
| Grade 8 | 20-30µm | White filter paper with printed green lines for optical assessment. For routine investigations of foreign substances in a variety of sample types. |
| Grade Shark Skin | 8-12 µm | Creped, medium/slow filter paper resistant to weak acids and bases. Used as protective paper for filter press cloths and processing of cocoa butter and edible oils. These filter papers are made from super-refined cellulose and have been specifically designed to have particular properties for each technical application. The applications range from the filtration of beverages to the purification of electroplating baths. |
| Grade 113 | 30 µm | Ultra-high loading capacity with particle retention well suited for use with coarse or gelatinous precipitates. The fastest flow rate of the qualitative grades. Creped surface. Thickest filter paper in the qualitative range. |
| Grade 2V | 8 µm | Folded Prepleated. Grade 2V pre-folded filter sheets are suitable for extracting samples from soil to support contaminant testing in the presence of weakly acidic solutions. |
| Grade 113V | 30 µm | Folded Prepleated. Ultra-high loading capacity with particle retention well suited for use with coarse or gelatinous precipitates. The fastest flow rate of the qualitative grades. Creped surface. Thickest filter paper in the qualitative range. |
| Grade 40 | 8 µm | High-purity filters support accurate analysis in applications sensitive to very low levels of background contamination and in a gravimetric analysis where ash content might affect weight measurements of combusted samples. GE’s high-purity Whatman Grade 40 ashless paper is suited for the following: Soil analysis when separating solid matter from aqueous extracts. Quantitative determination of milk sediment. Use as a clean-up filter for solutions prior to atomic absorption (AA) spectrometry. Analysis of constituent components in cements, clays, iron, and steel products. Collection of trace elements and radionuclides from the atmosphere. |
| Grade 41 | 20µm | GE’s Whatman Grade 41 environmental pollution papers are among the fastest filter papers in the Whatman ashless range. This gravimetric filter is well suited for quantitative analysis of soil and air. |
| Grade 42 | 2.5 µm | With the finest retention of all Whatman ashless filter paper grades, Grade 42 is designed for gravimetric analysis and sample preparation for instrumental analysis. Whatman ashless quantitative filter papers are high-purity filters that support accurate analysis in applications sensitive to very low levels of background contamination and in a gravimetric analysis where ash content might affect weight measurements of combusted samples. GE’s high-purity Whatman ashless filter papers are suited for: Environmental analysis: soil filtration analysis, when separating solid matter from aqueous extracts. Retention of small particles. Collection of trace elements and radionuclides from the atmosphere. |
| Grade 50 | 2.7 µm | GE’s thinnest Whatman brand hardened filter paper, highly glazed Grade 50 supports vacuum filtration in Büchner funnels or Hirsch funnels and enables strong retention of very fine crystalline precipitates. For many vacuum filtration applications, a thin filter paper with a slow flow rate and excellent wet strength can maintain sample quality and purity. Because Grade 50 thin filter papers are hardened to minimize fiber shredding, they are a good choice for use as carriers in integrated circuits. Grade 50 thin filter paper from GE Healthcare’s Life Sciences business is very strong when wet. It will withstand wet handling and precipitate removal by scraping. |
| Grade 52 | 7 µm | GE’s Whatman Grade 52 is a general-purpose filter paper for quantitative analysis in Büchner funnel and other vacuum filtrations. The acid-hardened surface and low ash content enable efficient precipitate recovery. |
| Grade 540 | 8 µm | GE’s hardened, ashless Grade 540 lab filter paper is frequently used as a gravimetric filter during the analysis of metals in acidic or alkaline solutions and in the collection of hydroxides. The acid-treated surface prevents tearing during filtration and allows the user to scrape precipitates from the paper. |
| Grade 541 | 22µm | GE’s Whatman Grade 541 acid hardened cellulose filter paper features high wet-strength, high chemical resistance, and large nominal particle retention for fast analytical filtration. Hardened ashless filter paper is recommended when fast filtration of a gelatinous precipitate for gravimetric analysis is performed on a strongly acidic or alkali solution. Applications of Grade 541 papers include: Use as an animal foodstuff filter for determining fiber content. Determination of gelatin content in milk and cream. Quantification of chloride in cement, as well as chloride and phosphorous in coal and coke. |
| Grade 542 | 2.7 µm | Hardened Grade 542 quantitative papers enable high retention of fine particles in chemically harsh conditions. When acting as a gravimetric filter, this cellulose filter paper is therefore well suited for use in capturing fine precipitates in applications such as metal determinations and hydroxide collection. |
| Grade 934-AH RTU | 1.5 μm | Pre-weighed and prewashed, this ready-to-use (RTU) Whatman Glass Microfiber Filter Papers are the time-saving version of GE’s 934-AH glass microfiber filter papers. Use for total suspended solids analysis, dissolved solids, and volatiles. The pre-weighed glass microfiber filter papers are packaged with a barcoded aluminum pan noting the filter paperweight. |
