Table 8 Microscopic findings in the lungs of male and female rats 24 h and 90 days after a 90-day exposure to Graphistrength^© C100

Target concentration (mg/m³)

0

0.05

0.25

5.0

0

0.05

0.25

5.0

Number examined

10/10

10/10

10/10

10/10

10/10

10/10

10/10

10/10

(24 h/90 days)

Black particle deposition

trace

-

-/10

-

-

-

-/10

-

-

minimal

-

9/-

-/10

-

-

10/-

2/10

-

slight

-

-

10/-

-

-

-

8/-

-

moderate

-

-

-

-/2

-

-

-

4/3

marked

-

-

-

10/8

-

-

-

6/7

Mean severity^a

-

0.9/0.5

2.0/1.0

4.0/3.8

-

1.0/0.5

1.8/1.0

3.6/3.7

Alveolar macrophages

minimal

-

-

8/10

-/1

-

-

9/10

-

slight

-

-

-

-/3

-

-

-

1/8

moderate

-

-

-

10/6

-

-

-

9/2

Mean severity^a

-

0.0

0.8/1.0

3.0/2.5

-

-

0.9/1.0

2.9/2.2

Alveolar eosinophilic material

minimal

-

-

-

6/8

-

-

-

4/4

slight

-

-

-

2/2

-

-

-

4/5

moderate

-

-

-

1/-

-

-

-

1/-

Mean severity^a

-

-

-

1.3/1.2

-

-

-

1.5/1.4

Alveolar granulocyte infiltration

minimal

-

-

-

10/8

-

-

-

10/7

Mean severity^a

-

-

-

1.0/0.8

-

-

-

1.0/0.7

Interstitial inflammation

minimal

-

-

-

-/1

-

-

-

4/5

slight

-

-

-

10/9

-

-

-

6/5

Mean severity^a

-

-

-

2.0/1.9

-

-

-

1.6/1.5

Bronchiolar cell hypertrophy/hyperplasia

minimal

-

-

-

10/-

-

-

-

10/-

Mean severity^a

-

-

-

1.0/-

-

-

-

1.0/-

Focal/multifocal collagen depositions, alveolar septa

minimal

-

-

-

-

-

-

-

-/2

slight

-

-

-

-/2

-

-

-

-

Mean severity^a

-

-

-

-/0.4

-

-

-

-/0.2

Increased lymphocytes, BALT ^b

minimal

-

-

-

2/-

-

-

-

2/-

slight

-

-

-

1/-

-

-

-

-

Mean severity

-

-

-

0.4/-

-

-

-

0.2/-