Return to Pyridalyl Index Page

Activity: Iinsecticide (unclassified)
Structure:

Adverse Effects:
Blood
Body Weight Decrease
Endocrine: Adrenal
Endocrine: Ovary
Endocrine: Testes
Kidney
Liver
Lung
Reproductive
Spleen
Environmental - persistence in soil

Subchronic toxicity.
-- Pyridalyl technical was tested in rats in a 3-month feeding study. Effects included decreased body weight gain, altered blood biochemistry, increased relative liver weight and histopathological changes in the liver, ovary, adrenal and lung. The NOAEL is 100 ppm (5.56 mg/kg/day in males and 6.45 mg/kg/day in females).
-- A 13-week feeding study in mice was conducted. Effects included decreased body weight gain, hematological and blood biochemical effects,increased liver weight, decreased kidney and ovary weights and histopathological changes in liver, kidney, ovary and adrenal. The NOAEL is 70 ppm in males (8.169 mg/kg/day) and 700 ppm in females (86.78 mg/kg/day).
-- A 13-week oral (capsule) toxicity study was conducted in dogs. Effects included decreased body weight gain, clinical signs indicative of respiratory distress, hematological and blood biochemistry effects, increased liver, lung and kidney weights and histopathological alterations of the lung, kidney, adrenal and liver. The NOAEL was 10 mg/kg/day.
Chronic toxicity.
-- In a 104-week combined chronic/oncogenicity study in rats,
effects included decreased body weight gain, increased frequency of rearing (high dose females only), hematological alterations and histopathological alterations of the spleen. No oncogenicity was found. The NOAEL for this study is 100 ppm (3.4 mg/kg/day in males and 4.1 mg/kg/day in females).
-- Pyridalyl was administered for 12-months by capsule to dogs. There were alterations in blood biochemistry (alkaline phosphatase and alanine aminotransaminase) and increased liver weights. The NOAEL of the study was 20 mg/kg/day.
Ref: Federal Register: December 5, 2003. Pyridalyl; Notice of Filing a Pesticide Petition.
http://www.fluorideaction.org/pesticides/pyridalyl.fr.dec.5.2003.htm

Body Weight Decrease (click on for all fluorinated pesticides)

Subchronic toxicity.
-- Pyridalyl technical was tested in rats in a 3-month feeding study. Effects included decreased body weight gain, altered blood biochemistry, increased relative liver weight and histopathological changes in the liver, ovary, adrenal and lung. The NOAEL is 100 ppm (5.56 mg/kg/day in males and 6.45 mg/kg/day in females).
-- A 13-week feeding study in mice was conducted. Effects included decreased body weight gain, hematological and blood biochemical effects,increased liver weight, decreased kidney and ovary weights and histopathological changes in liver, kidney, ovary and adrenal. The NOAEL is 70 ppm in males (8.169 mg/kg/day) and 700 ppm in females (86.78 mg/kg/day).
-- A 13-week oral (capsule) toxicity study was conducted in
dogs. Effects included decreased body weight gain, clinical signs indicative of respiratory distress, hematological and blood biochemistry effects, increased liver, lung and kidney weights and histopathological alterations of the lung, kidney, adrenal and liver. The NOAEL was 10 mg/kg/day.
Chronic toxicity.
-- In a 104-week combined chronic/oncogenicity study in rats,
effects included decreased body weight gain, increased frequency of rearing (high dose females only), hematological alterations and histopathological alterations of the spleen. No oncogenicity was found. The NOAEL for this study is 100 ppm (3.4 mg/kg/day in males and 4.1 mg/kg/day in females).
-- Pyridalyl was administered in the diet to mice for 78-weeks. Effects included decreased body weight gain and food consumption/efficiency, and increased liver and kidney weights. The NOAEL of the study was 50 ppm (5.04 mg/kg/day in males and 4.78 mg/kg/day in females)
Ref: Federal Register: December 5, 2003. Pyridalyl; Notice of Filing a Pesticide Petition.
http://www.fluorideaction.org/pesticides/pyridalyl.fr.dec.5.2003.htm

Endocrine: Adrenal (click on for all fluorinated pesticides)

Subchronic toxicity.
-- Pyridalyl technical was tested in rats in a 3-month feeding study. Effects included decreased body weight gain, altered blood biochemistry, increased relative liver weight and histopathological changes in the liver, ovary, adrenal and lung. The NOAEL is 100 ppm (5.56 mg/kg/day in males and 6.45 mg/kg/day in females).
-- A 13-week feeding study in mice was conducted. Effects included decreased body weight gain, hematological and blood biochemical effects,increased liver weight, decreased kidney and ovary weights and histopathological changes in liver, kidney, ovary and adrenal. The NOAEL is 70 ppm in males (8.169 mg/kg/day) and 700 ppm in females (86.78 mg/kg/day).
-- A 13-week oral (capsule) toxicity study was conducted in
dogs. Effects included decreased body weight gain, clinical signs indicative of respiratory distress, hematological and blood biochemistry effects, increased liver, lung and kidney weights and histopathological alterations of the lung, kidney, adrenal and liver. The NOAEL was 10 mg/kg/day.
Ref: Federal Register: December 5, 2003. Pyridalyl; Notice of Filing a Pesticide Petition.
http://www.fluorideaction.org/pesticides/pyridalyl.fr.dec.5.2003.htm

Endocrine: Ovary (click on for all fluorinated pesticides)

Subchronic toxicity.
-- Pyridalyl technical was tested in rats in a 3-month feeding study. Effects included decreased body weight gain, altered blood biochemistry, increased relative liver weight and histopathological changes in the liver, ovary, adrenal and lung. The NOAEL is 100 ppm (5.56 mg/kg/day in males and 6.45 mg/kg/day in females).
-- A 13-week feeding study in mice was conducted. Effects included decreased body weight gain, hematological and blood biochemical effects,increased liver weight, decreased kidney and ovary weights and histopathological changes in liver, kidney, ovary and adrenal. The NOAEL is 70 ppm in males (8.169 mg/kg/day) and 700 ppm in females (86.78 mg/kg/day)
Ref: Federal Register: December 5, 2003. Pyridalyl; Notice of Filing a Pesticide Petition.
http://www.fluorideaction.org/pesticides/pyridalyl.fr.dec.5.2003.htm

Endocrine: Testes (click on for all fluorinated pesticides)

Possible effect of pyridalyl on the steroid synthesis pathway was surveyed in rats. It was revealed that pyridalyl affected the sex hormone synthetic pathway in the testis at the concentration of 3 µM and higher, and this effect was caused by an inhibition of testosterone synthesis, via weak but significant inhibition of 17a-HSD activity. (Ref. 44. Effect of pyridalyl on the sexual hormonal synthetic pathway in rats: Sumitomo Chemical Co., Ltd., 2002, unpublished.)
Ref: Evaluation Report. PYRIDALYL. January 14, 2004. Japan Food Safety Commission. Pesticides Expert Committee.

Kidney (click on for all fluorinated pesticides)

Subchronic toxicity.
-- A 13-week feeding study in mice was conducted. Effects included decreased body weight gain, hematological and blood biochemical effects,increased liver weight, decreased kidney and ovary weights and histopathological changes in liver, kidney, ovary and adrenal. The NOAEL is 70 ppm in males (8.169 mg/kg/day) and 700 ppm in females (86.78 mg/kg/day).
-- A 13-week oral (capsule) toxicity study was conducted in
dogs. Effects included decreased body weight gain, clinical signs indicative of respiratory distress, hematological and blood biochemistry effects, increased liver, lung and kidney weights and histopathological alterations of the lung, kidney, adrenal and liver. The NOAEL was 10 mg/kg/day.
Chronic toxicity.
-- Pyridalyl was administered in the diet to mice for 78-weeks. Effects included decreased body weight gain and food consumption/efficiency, and increased liver and kidney weights. The NOAEL of the study was 50 ppm (5.04 mg/kg/day in males and 4.78 mg/kg/day in females)
Ref: Federal Register: December 5, 2003. Pyridalyl; Notice of Filing a Pesticide Petition.
http://www.fluorideaction.org/pesticides/pyridalyl.fr.dec.5.2003.htm

Liver (click on for all fluorinated pesticides)

Subchronic toxicity.
-- Pyridalyl technical was tested in rats in a 3-month feeding study. Effects included decreased body weight gain, altered blood biochemistry, increased relative liver weight and histopathological changes in the liver, ovary, adrenal and lung. The NOAEL is 100 ppm (5.56 mg/kg/day in males and 6.45 mg/kg/day in females).
-- A 13-week feeding study in mice was conducted. Effects included decreased body weight gain, hematological and blood biochemical effects, increased liver weight, decreased kidney and ovary weights and histopathological changes in liver, kidney, ovary and adrenal. The NOAEL is 70 ppm in males (8.169 mg/kg/day) and 700 ppm in females (86.78 mg/kg/day).
-- A 13-week oral (capsule) toxicity study was conducted in
dogs. Effects included decreased body weight gain, clinical signs indicative of respiratory distress, hematological and blood biochemistry effects, increased liver, lung and kidney weights and histopathological alterations of the lung, kidney, adrenal and liver. The NOAEL was 10 mg/kg/day.
Chronic toxicity.
-- Pyridalyl was administered in the diet to mice for 78-weeks. Effects included decreased body weight gain and food consumption/efficiency, and increased liver and kidney weights. The NOAEL of the study was 50 ppm (5.04 mg/kg/day in males and 4.78 mg/kg/day in females)
-- Pyridalyl was administered for 12-months by capsule to
dogs. There were alterations in blood biochemistry (alkaline phosphatase and alanine aminotransaminase) and increased liver weights. The NOAEL of the study was 20 mg/kg/day.
Ref: Federal Register: December 5, 2003. Pyridalyl; Notice of Filing a Pesticide Petition.
http://www.fluorideaction.org/pesticides/pyridalyl.fr.dec.5.2003.htm

Lung (click on for all fluorinated pesticides)

Subchronic toxicity.
-- Pyridalyl technical was tested in rats in a 3-month feeding study. Effects included decreased body weight gain, altered blood biochemistry, increased relative liver weight and histopathological changes in the liver, ovary, adrenal and lung. The NOAEL is 100 ppm (5.56 mg/kg/day in males and 6.45 mg/kg/day in females).
-- A 13-week oral (capsule) toxicity study was conducted in
dogs. Effects included decreased body weight gain, clinical signs indicative of respiratory distress, hematological and blood biochemistry effects, increased liver, lung and kidney weights and histopathological alterations of the lung, kidney, adrenal and liver. The NOAEL was 10 mg/kg/day.
Ref: Federal Register: December 5, 2003. Pyridalyl; Notice of Filing a Pesticide Petition.
http://www.fluorideaction.org/pesticides/pyridalyl.fr.dec.5.2003.htm

Reproductive (click on for all fluorinated pesticides)

Species	Evaluation Test	NOAEL	Note
Rat	Two-generation reproductive toxicity study	P Male: 2.80 mg/kg bw/day P Female: 3.11 mg/kg bw/day F1 Male: 3.40 mg/kg bw/day F1 Female: 3.62 mg/kg bw/day	Delayed sexual maturation in females
Ref: Evaluation Report. PYRIDALYL. January 14, 2004. Japan Food Safety Commission. Pesticides Expert Committee.

Spleen (click on for all fluorinated pesticides)

Chronic toxicity.
-- In a 104-week combined chronic/oncogenicity study in rats,
effects included decreased body weight gain, increased frequency of rearing (high dose females only), hematological alterations and histopathological alterations of the spleen. No oncogenicity was found. The NOAEL for this study is 100 ppm (3.4 mg/kg/day in males and 4.1 mg/kg/day in females).
Ref: Federal Register: December 5, 2003. Pyridalyl; Notice of Filing a Pesticide Petition.
http://www.fluorideaction.org/pesticides/pyridalyl.fr.dec.5.2003.htm