Investigation of the permanence of cellulose fibres in rats lungs

Project No. FFFF 0105


completed 09/1995


The classification of certain fibre-like dusts depending on fibre shape and biodegradability; suspicion that, according to these criteria, organic fibres also possess carcinogenic potential. Cellulose fibres are used in the paper and insulating material industries as well as for improvements to surfaces (flock-coating). Goal: animal tests to determine the biodegradability of cellulose fibres; evaluation of carcinogenic potential


Endotracheal instillation of two different cellulose fibre preparations (pure hardwood cellulose as the model substance and the commercial product "isofloc"); tracing the elimination of the fibres over a period of one year


The fibre dimensions L/D of the test substance are 7.7/0.45 µm, the model substance 4.2/0.87 µm. Both types of fibres were still present in the lung after one year, the pure cellulose fibre was unchanged. The decay periods were calculated as 1,000 days (pure cellulose) and 72 days (isofloc). With isofloc an unexplainable splitting into thinner fibres was observed.


Muhle u.a.: Investigation of the durability of cellulose fibres in rat lungs. Ann.occup.Hyg. Vol. 41 (1997) S. 184-188

Last Update:

2 Aug 2000


Financed by:
  • Hauptverband der gewerblichen Berufsgenossenschaften (HVBG)
Research institution(s):
  • Fraunhofer-Institut für Toxikologie und Aerosolforschung, Hannover

-cross sectoral-

Type of hazard:

dangerous substances


Gefährdungsbeurteilung, krebserregende Stoffe, Toxikologie

Description, key words:

Risks to health from organic fibres, period of decay of isofloc (cellulose) 72 days, length/diameter = 7.7/0.45 µm