Rounding off Figures of Analytical Results

Assay Calculation

• While doing any assay calculation the result of the assay is expressed up to one decimal place more than the significant figures stated and then the results are rounded up or down as follows.
• If the last figure calculated is 5 to 9, the preceding figure is increased by 1 & if it is 4 or less, the preceding figure is left unchanged.
• To find out significant figures for particular value refer to its specification limit, e.g. if the limit is 99.00 to 102.00 then two decimals from the decimal point are significant. If the limit is 98 to 101 then significant figures are without a decimal point.
• Microbial Limit Test Report: The reading of count expressed as a whole number. Pathogens reading is reported as Present / Absent / Positive / Negative.
• Water analysis / Slit Air Sampling / Bacterial Count / fungal Count / Settle Plate / Swab: Is expressed as a whole number.
• Microbial Assay: Any microbial assay is expressed either in terms of percentage/ microgram/ milligram.

Loss On Drying

The result of loss on drying is expressed in terms of percentage up to the second decimal place and the results are rounded up or down as mentioned in assay calculation.

Sulphated Ash

The result of sulfated ash is expressed in terms of percentage up to the fourth decimal place and the results are rounded up or down as mentioned in assay calculation.

Loss On Ignition

The result of loss on ignition is expressed in terms of percentage up to the second decimal place and the results are rounded up or down as mentioned in assay calculation.

HPLC Calculation

Area of standard & sample in Agilent series HPLC system is expressed up to the third decimal place, e.g. 237.293, 2.293 etc.
NOTE: Area of standard & sample in Thermo Separation series HPLC system is not expressed in the decimal place.

Impurity

Any Impurity is expressed up to the third decimal place, e.g. 0.101, 0.500 etc.

Absorbance measured on the Spectrophotometer

Absorbance is expressed up to the third decimal place, e.g. 0.101, 0.500 etc.

Gas Chromatography

Area of standard & sample is expressed up to the fourth decimal place.

Temperature & Humidity of Stability Ovens

Temperature & humidity of stability ovens is expressed up to one decimal place.

Temperature & Humidity of Control Sample Room

Temperature & humidity of control sample room is expressed as the actual temperature displayed on the Thermometer, e.g. 22°C, 25°C, etc.

Related: Requirements for Good Documentation Practice (GDP)

Bin Cards

Bin Cards of Raw Material:

When the material is received/issued in terms of kg, the quantity is expressed up to the third decimal place & when the material is received/issued in terms of g., the quantity is expressed up to the third decimal place.

Bin Cards of Packing Material:

• When printed packaging material like labels, cartons, leaflets, BOPP Tape, Corrugated boxes are issued, it is expressed in terms of numbers.
• When unprinted packaging material like containers, bottles are issued, it is expressed in terms of numbers. 
• Printed / unprinted foil when issued is expressed in terms of kg.

Batch Manufacturing Documents

When the material is weighed in terms of kg, the quantity is expressed up to the second decimal place & when the material is weighed in terms of g., the quantity is expressed up to the third decimal place. Percentage yield is expressed up to the second decimal place.