Acetic acid, oxo-, sodium salt, reaction products with ethylenediamine and phenol, iron sodium salts

Endpoint summary

Description of key information

In a 90-day oral (gavage) key repeated dose toxicity study in rats (Novartis Crop Protection AG, 1998), the NOAEL was established at 10 mg/kg bw/day based on a transient normochromic anaemia present at higher dose levels (estimated from LOAEL). Changes in clinical laboratory parameters noted at higher dose levels and indicative of effects on kidneys and/or liver were without microscopic correlate under the conditions of this study. A supporting and preceding 28-day dose range finding (oral gavage) study (CIBA-GEIGY Limited, 1996a) in rats provided further indication that the haematopoietic system and, at higher dose levels, the kidney represented target organs following repeated oral exposure. In a recently performed extended oral OECD 422 study with a pre-mating period of 10 weeks (therefore a total duration of at least 90 days), and in which all recent 90-day (OECD 408) study parameters have been included did not show parental toxicity at a level of 25 mg/kg bw/day. Mortality was observed at higher doses, and histopathological evaluation of the deceased or prematurely killed animals showed renal tubular degeneration and necrosis, hepatocellular degeneration and necrosis with and without hemorrhage, increased pigmented macrophages within splenic red pulp and medullary sinuses of mesenteric lymph nodes (draining lymph nodes of the intestinal tract), decreased lymphoid tissue of the thymus (atrophy), and compensatory responses within bone marrow of progenitor cells. Minimally increased numbers of pigmented macrophages within medullary sinuses of mesenteric lymph nodes and splenic red pulp, as well as an increased or decreased myeloid to erythroid ratio within sternal bone marrow were also seen in a few surviving animals at the mid and high dose; these findings together suggest increased red blood cell turnover in the affected animals and a compensatory response by bone marrow. 

In a key subacute 28-day dermal toxicity study (CIBA-GEIGY Limited, 1996b), the NOEL was established at 100 mg/kg bw/day based on slight effects on the liver and skin and due to increased adrenal weight noted at the high dose level of 1000 mg/kg bw/day. Exposure by the inhalation route is considered negligible.     

 

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Endpoint conclusion

Dose descriptor:

NOAEL

25 mg/kg bw/day

Study duration:

subchronic

Species:

rat

Additional information

Oral route

In a dose range-finding subacute oral toxicity study (CIBA-GEIGY Limited, 1996a), FeNa-EDDHA was administered to 5 Sprague-Dawley derived rats/sex/dose level by oral gavage at 50, 200 or 1000 mg/kg bw/day for 28 days. A concurrent control group was treated with the vehicle only. Treatment with the test item resulted in impaired body weight development at 200 and 1000 mg/kg bw/day and correspondent lower food intake. An anaemia without erythropoietic response was noted at 200 and 1000 mg/kg bw/day. At the same dose levels, the kidney was revealed as target organ by microscopical examination, by blood chemistry data evaluation and by organ weight evaluation. In addition, relative organ weight changes were noted in the heart, adrenals and spleen. However, the relevance of these findings was considered as equivocal. This study was used as scientific basis for dose level selection for the 90-day repeated dose oral toxicity study in the rat.

The subchronic (90-day) toxicity by the oral route was investigated in rats (Novartis Crop Protection AG, 1998). The test item FeNa-EDDHA was administered to 10 Sprague-Dawley derived rats/sex/dose level by oral gavage at 5, 50 or 200 mg/kg bw/day for 90 days. A concurrent control group was treated with the vehicle only. Additional 10 animals/sex of the high dose and control group were kept on control diet for a 4-week recovery period before sacrifice. Treatment with the test item resulted in lower food intake and impared body weight development at 200 mg/kg bw/day. Reversible effects on red blood cell (normochromic anaemia) and white blood cell parameters, and higher values of platelets and prothrombin activity were noted at 50 and/or 200 mg/kg bw/day. In addition, changes of blood chemistry and urine parameters concerning the liver and kidneys were noted. The body weight relative heart weight was increased in males at 200 mg/kg bw/day. Under the conditions of this study, the NOAEL for FeNaEDDHA when administered by daily oral gavage for three months was 10 mg/kg bw/day (estimated from the LOAEL). 

A recently performed extended oral OECD 422 study with a pre-mating period of 10 weeks (therefore a total duration of at least 90 days for both males and females), and in which all recent 90-day (OECD 408) study parameters have been included, did not show parental toxicity at a level of 25 mg/kg bw/day. Mortality was observed at higher doses, and histopathological evaluation of the deceased or prematurely killed animals showed renal tubular degeneration and necrosis, hepatocellular degeneration and necrosis with and without hemorrhage, increased pigmented macrophages within splenic red pulp and medullary sinuses of mesenteric lymph nodes (draining lymph nodes of the intestinal tract), decreased lymphoid tissue of the thymus (atrophy), and compensatory responses within bone marrow of progenitor cells. Minimally increased numbers of pigmented macrophages within medullary sinuses of mesenteric lymph nodes and splenic red pulp, as well as an increased or decreased myeloid to erythroid ratio within sternal bone marrow were also seen in a few surviving animals at the mid and high dose; these findings together suggest increased red blood cell turnover in the affected animals and a compensatory response by bone marrow.

Based on these two studies of at least 90-day duration the overall NOAEL was set at 25 mg FeNa-EDDHA/kg bw/day. 

When comparing these two oral 90-day repeated dose studies the following should be noted:

- for males, there was no mortality in the standard earlier 90-day study up to and including the high dose of 200 mg/kg bw/day whereas treatment with the test item resulted in lower food intake and impared body weight development of these rats. In the extended OECD 422 study, one male of the high dose group (at that time 300 mg/kg bw) was prematurely sacrificed on Day 31 due to significant BW loss. No mortality was noted at 85 mg/kg bw/day. Body weight gain between Day 71 and 91/92 for the male rats was 4.5%, 5.9%, 4.5% and 4.3% for the control, 25, 85 and 300/225/175 mg/kg bw/day group, respectively. 

- for females, there was also no mortality in the standard earlier 90-day study at the high dose of 200 mg/kg bw/day whereas treatment with the test item resulted in lower food intake and impared body weight development of these rats. In this study, the females were not pregnant. In the extended OECD 422 study, with pregnant females, several females of the high dose group (300/225/200/175 mg/kg bw/day) were found dead at the end of the gestation period due to parturition difficulties which was secondary to maternal toxicity as noted in bodyweight and food consumption findings. Also at 85 mg/kg/bw/day, one female was found dead and three sacrificed at the end of the gestation period for the same reasons. However, when compared to male rats (see above), body weight gain for the female rats between Day 0 and 20 of gestation (between ca. Day 71 and 91/92 of the study) was much higher in this period viz. 46%, 44%, 35% and 30% for the control, 25, 85 and 300/225/175 mg/kg bw/day group, respectively. This means that e.g. at the dose of 85 mg/kg bw/day, if body weight gain would have been the same for male and non-pregnant female rats during this period, viz. 4.5% for both rather than 35% for pregnant females, females were given 30% more of FeNa-EDDHA during pregnancy compared to non-pregnancy, thus in fact 1.3 times more, or 110 mg/kg bw/day (subtracting the weight of the uterus and its content). Overall, pregnant females seem to be substantially more sensitive than non-pregnant females.      

Dermal route

In a repeated dose dermal toxicity study (CIBA-GEIGY Limited, 1996b), FeNaEDDHA was administered to the skin of 5 Sprague-Dawley derived rats/sex/dose level at 10, 100 or 1000 mg/kg bw/day for 28 days (5 days/week). A concurrent control group was treated with the vehicle only. Dermal treatment with the test item resulted in no mortality, no relevant clinical signs, no changes in food consumption, no effects on haematology and clinical chemistry parameters and no gross findings. A transient slight body weight loss was noted in females at 1000 mg/kg bw/day during the first week of treatment. There was an increase in adrenal weight in males at 1000 mg/kg bw/day. Microscopically, the skin application sites of females at 1000 mg/kg bw/day revealed epidermal hyperkeratosis associated with an increased severity of acanthosis. In 2/5 males at 1000 mg/kg bw/day centrilobular hypertrophy of hepatocytes was noted. Based on the slight effects on the liver and skin and due to the increased adrenal weight noted at 1000 mg/kg bw/day, the NOEL was established at 100 mg/kg bw/day.

Inhalation route

In accordance with column 2 of REACH Annex IX, the test repeated dose toxicity after inhalation (required in section 8.6) does not need to be conducted as repeated dose toxicity studies for oral and dermal application are available. Inhalation exposure is regarded negligible as the particle size distribution for particles below 100 µm were found to be 2.7% and no particles were found less than 10 µm. In addition, the substance showed only very low toxicity following an acute inhalation exposure resulting in a 4-h LC50 greater than 4200 mg/m³ in the rat (technically maximally attainable concentration).

 

Justification for classification or non-classification

The available experimental test data are reliable and appropriate for classification purposes under Regulation (EC) No 1272/2008. Based on the results of the key repeated dose toxicity studies (of at least 90 days) with special regard to specific target organ toxicity after repeated exposure, considering the NOAEL of 25 mg/kg bw/day established for the oral route together with the absence of significant toxicity up to 100 mg/kg bw/day in males and non-pregnant females, the substance is not subject to classification and labelling according to Regulation (EC) No 1272/2008.