Microscopic analysis


The analysis of light filth test allows to detect light solid impurities of mineral, vegetable or animal origin, and gives information about conditions and modes of preparation, conservation and distribution.
The analysis is applicable to cereals and by-products (flours, pasta and bakery products), fresh and conserved vegetables, spices, coffee, cocoa, milk and by-products, mushrooms.


This analysis allows to detect and count:

  • Whole insects or insect fragments
  • Rodent or other mammals hairs
  • Feathers
  • Mites
  • Carbonaceous particles
  • Natural and synthetic fibres

Analytical techniques

The laboratory can apply the following methods:

  • Ministerial decree dated 12.01.99, official method of analysis for cereals. Official Gazette – Determination of solid impurities (filth test) in flours and processed products.
  • Official methods of analysis AOAC international.
  • ISO method 11050, wheat flour and durum wheat semolina. Determination of impurities of animal origin.


Accreditation by Accredia (Italian Accreditation Body) according to UNI CEI EN ISO/IEC 17025 standard.
[Accreditation number: 0026, Certificate first emission: 14/11/1991]

The specific accredited tests are:

  • Light filth test in pasta, AOAC 969.41 ed 18th 2005 method
  • Light filth test in white flour, AOAC 972.32 ed 18th 2005 method
  • Light filth test in bread and high fat content product, AOAC 970.70 ed 18 th 2005 method
  • Light filth test in white flour and durum wheat, ISO 11050:1993 method
  • Filth test in coffee beans, FDA – Technical Bulletin n°5 chapter V-1A excluded- Paragraph (4.e)

The systematic involvement in Proficiency Tests organized by BIPEA provides the external evidence about the test methods applied.
The full reports and the corresponding identification codes of Proficiency Test performed in the last year are available. To request the last P-Tests results, please contact Quality Assurance.

Legislative References

Simple Act of Parliament n° 283, 30/04/1962 Amendment of art. 242, 243, 247, 250 and 262 of T.U. of health laws approved with R.D. 27 July 1934, n. 1265: Hygienic discipline of production and sale of foodstuffs and beverages. Art.5


Tests on new AOAC methods to increase the number of analyzable matrices.


Respecting Regulation EU n° 51 / 2013 the analysis of constituents of animal origin provides the detection and recognition of these constituents using optical microscopy (semi-quantitative analysis)

  • Accreditation for feedings and raw materials
  • Participation to Proficiency Tests organized by Creea


Observation of the sample under examination  at various magnifications to stereoscope and  microscope.
Utilization of reagents and/or dyes in order to detect the nature of the object.


Microplastics are fragments with indefinite shape (fibers, spheroids, granules, pellets, etc.) and can be heterogeneous mixtures of different materials.
In literature there are several studies showing that microplastics pollution has reached the food chain, affecting not only marine wildlife, but also foodstuffs such as sea salt, beer and honey.
A study published on Environmental Science and Technology, result of a data processing of 26 studies measuring the amount of microplastics in fish, crustaceans, sugar, salt, beer, water and other matrices, shows that human being would be exposed to a quantity of about 50,000 fragments per year derived from the diet. If we consider those introduced by breathing, we would arrive at an estimated intake between 70,000 and 121,000 particles per year1.
These numbers cause concern in the scientific community and appear as an alert mainly because the toxicity of microplastics or the path followed in the body after their ingestion are not yet clear2.


Our analytical purpose includes several matrices such as water, salt, sugar, honey and beer. Given the importance of this subject, we expect to perform the test on matrices such as milk, tuna, molluscs, etc. Our method based on selective staining with specific fluorescent dye allows us to isolate, measure and count microplastics down to 8-10 microns.
The fragments are isolated by filtration and subsequently observed to the stereo fluorescence microscope that allows to measure and count the microplastics that may be present. At the same time, a blank test of the materials used is performed in order to avoid overestimation of fragments due to possible contamination. Photographs of the detected fragments can be shared to the customer.
To date there are no reference standards for the assessment of the values found; an approach for comparison is therefore suggested.

1 Human Consumption of Microplastics, Environ. Sci. Technol .2019, 53, 12, 7068-7074
2 Microplastics and nanoplastics in food: an emerging issue, interview to Dr. Peter Hollman, EFSA.

Latest update: 11/07/2019 17:04:12