Phosphoric acid, C16-18-alkyl esters, potassium salts

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Effect on fertility: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

1 000 mg/kg bw/day

Study duration:

subchronic

Species:

rat

Quality of whole database:

The key study is of high quality with Klimisch score = 1; the reliability was changed from RL1 to RL2 to reflect the fact that this study was conducted on a read-across substance.

Effect on fertility: via inhalation route

Endpoint conclusion:

no study available

Effect on fertility: via dermal route

Endpoint conclusion:

no study available

Additional information

Reliable, relevant and adequate data on reproductive toxicity are available for the read-across substance Phosphoric acid, dodecyl ester, sodium salt.

The read-across approach is appropriate due to similar composition of source substance and registered substance. From the available data is can be concluded that the repeated dose toxicity of substances with different alkyl moieties (C12, C14, C9-15 linear and branched) is comparable.

Phosphoric acid alkyl esters are hydrolysed unspecifically by phosphatases, e.g. acid phosphatase or alkaline phosphatase. Both enzymes are found in most organisms from bacteria to human. Alkaline phosphatases are present in all tissues, but are particularly concentrated in liver, kidney, bile duct, bone, placenta. In human and most other mammals three isoenzymes of Alkaline phosphatase exist: intestinal ALP, placental ALP, tissue non-specific ALP (present in bone, liver, kidney, skin).

Seven different forms of Acid phosphatase are known in humans and other mammals. These are also present in different tissues and organs (predominantly erythrocytes, liver, placenta, prostate, lung, pancreas).

Linear and branched primary aliphatic alcohols are oxidised to the corresponding carboxylic acid, with the corresponding aldehyde as a transient intermediate. The carboxylic acids are further degraded via acyl-CoA intermediates in by the mitochondrial beta-oxidation process. Branched aliphatic chains can be degraded via alpha- or omega-oxidation (see common text book on biochemistry).

“The long chain aliphatic carboxylic acids are efficiently eliminated and aliphatic alcohols are therefore not expected to have a tissue retention or bioaccumulation potential (Bevan, 2001).

Longer chained aliphatic alcohols within this category may enter common lipid biosynthesis pathways and will be indistinguishable from the lipids derived from other sources (including dietary glycerides) (Kabir, 1993; 1995a,b).

A comparison of the linear and branched aliphatic alcohols shows a high degree of similarity in biotransformation. For both sub-categories the first step of the biotransformation consists of an oxidation of the alcohol to the corresponding carboxylic acids, followed by a stepwise elimination of C2 units in the mitochondrial β-oxidation process. The metabolic breakdown for both the linear and mono-branched alcohols is highly efficient and involves processes for both sub-groups of alcohols. The presence of a side chain does not terminate the β-oxidation process, however in some cases a single Carbon unit is removed before the C2 elimination can proceed.” (OECD SIDS, 2006).

 

Thus, it can be expected, that also the effects on reproduction of the Phosphoric acid C12-alkyl ester will be similar to those of Phosphoric acid, mono- and di- C16-18 (even numbered) alkyl esters.

 

In a Combined Repeated Dose Toxicity Study with the Reproduction/Developmental Toxicity Screening Test according to OECD guideline 422 Phosphoric acid, dodecyl ester, sodium salt was administered to 12 Sprague-Dawley rats/sex/dose by daily oral gavage at dose levels of 0 (control), 250, 500, and 1000 mg/kg bw/d.

The males were exposed 14 days before mating, through the mating period, up to 1 day before termination (42 days in total). The females were exposed 14 days before mating, through the mating and gestation period, up to day 4 of lactation (42 to 45 days in total).

Administration of the test substance did not have any effect on the estrous cycle, days to copulation, copulation rate, fertility rate, or conception rate. Similarly, administration of the test substance did not have any effect on the delivery rate, gestation period, number of corpora lutea, number of implantation sites, implantation rate, stillbirth rate, number of live-born pups, live-birth rate in the mother animals, or on the sex ratio of the littermates. No abnormalities were observed in the lactating behaviour during the lactation period either. These results suggest that administration of the test substance even at 1000 mg/kg had no effect on the reproductive function, such as that shown by the copulation rate, of the males or females, or in the fertility rate, conception rate, or on the gestation maintenance, delivery, or lactating behaviour in the mother animals.

Pups showed no changes caused by the administration of the test substance regarding the observation at birth, necropsy findings on day 4 of lactation, body weight, or viability rate, which suggested that administration of the test substance even at 1000 mg/kg bw/d had no effect on the development.

The reproduction, breeding and developmental NOEL is 1000 mg/kg bw/d.

Higher-tier fertility study (two-generation study) is not required, since there were no adverse effects observed in the repeated dose toxicity study in reproductive organs or tissues or any adverse effects in the screening studies for reproductive toxicity (OECD 422). Therefore, there is no data gap in fertility. There is no reason to believe that results of the screening study would not be relevant for fertility in humans and therefore, for risk assessment.

Short description of key information:

Combined Repeated Dose Toxicity Study with the Reproduction/Developmental Toxicity Screening Test oral (gavage), rat (Sprague-Dawley) m/f (OECD guideline 422, GLP no data): reproduction, breeding and developmental NOEL: 1000 mg/kg bw/day (both sexes); read-across substance Phosphoric acid, dodecyl ester, sodium salt

Justification for selection of Effect on fertility via oral route:

OECD guideline study, no deviations, GLP

Effects on developmental toxicity

Description of key information

Prenatal developmental toxicity study: rat (Sprague-Dawley Crl:CD® BR),  gavage, (OECD 414): NOEL developmental toxicity, embryotoxicity, fetotoxicity and teratogenicity 361 mg/kg bw/d (highest dose administered).  No compound related developmental toxicity, embryotoxicity, fetotoxicity or teratogenicity has been observed in a developmental toxicity study with Phosphoric acid, C9-15 branched and linear alkyl esters, potassium salts.  

Link to relevant study records

Reference

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1994-01-07 to 1994-11-09

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

Deviations:

yes

Remarks:

: Analytical verification (homogeneity, stability and concentration) of the test material formulations was not performed.

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Species:

rat

Strain:

other: Sprague-Dawley Crl:CD® BR rats

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation (females): 13 weeks
- Weight at study initiation (females): minimum 220 g (215 to 291 g on day 0 of gestation)
- Fasting period before study: no
- Housing: wire-mesh cage
- Diet (e.g. ad libitum): Purina Certified Rodent Chow #5002, ad libitum
- Water (e.g. ad libitum): tap water, ad libitum
- Acclimation period: 19 days

ENVIRONMENTAL CONDITIONS
- Temperature (°F): 67°F to 74°F
- Humidity (%): 28% to 58%
- Air changes (per hr): 10
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: To: 1994-01-11 to 1994-02-4

Route of administration:

oral: gavage

Vehicle:

water

Remarks:

deionized water, prepared on site

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:
An appropriate amount of test material, alkyl potassium phosphate, was weighed for each group into a tared precalibrated storage container. A sufficient amount of vehicle, deionized water, was added to bring the suspension to the appropriate volume. The preparations were stirred using a magnetic stir bar continuously during the dosing procedure. All dosing preparations were visually inspected by the Study Director on the first day of administration and appeared to be homogeneous and acceptable for administration. Preparations for all dose groups were made daily and were stored at room temperature. Analytical chemistry determinations to establish homogeneity, stability and concentration were not required by the protocol and were not conducted.

Analytical verification of doses or concentrations:

no

Details on analytical verification of doses or concentrations:

Dosage calculations were not adjusted for puritiy. The bulk material was 36.1% pure (as the potassium salt).

Details on mating procedure:

- Impregnation procedure: cohabitation
- If cohoused:
- M/F ratio per cage: 1 to 1
- Length of cohabitation: not given - Each mating pair was examined daily. Positive evidence of mating was confirmed by the presence of a copulatory plug or the presence of sperm in a vaginal smear. Each mating pair was examined daily. The day on which evidence of mating was identified was termed day 0 of gestation and the animals were separated.
- Verification of same strain and source of both sexes: yes
- Resident males were from the same strain and source.
- Resident males were untreated, sexually mature rats utilized exclusively for breeding
- Proof of pregnancy: vaginal plug or sperm in vaginal smear referred to as day 0 of pregnancy
- Any other deviations from standard protocol: After mating, female rats were removed and allocated to the test groups.

Duration of treatment / exposure:

10 consecutive days initiating on gestation day 6 and continuing up to and including day 15 of gestation

Frequency of treatment:

once daily

Duration of test:

Females were sacrificed on day 21 post coitum.

Remarks:

Doses / Concentrations:
0 mg/kg bw/day (vehicle control)
Basis:
actual ingested
active ingredient

Remarks:

Doses / Concentrations:
36.1 mg/kg bw/day
Basis:
actual ingested
active ingredient

Remarks:

Doses / Concentrations:
180.5 mg/kg bw/day
Basis:
actual ingested
active ingredient

Remarks:

Doses / Concentrations:
361 mg/kg bw/day
Basis:
actual ingested
active ingredient

No. of animals per sex per dose:

25/group.

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: Dosages were based on the results of the dose range-finding sudy
- Rationale for animal assignment (if not random): The first mated female and the appropriate gestation day 0 designation were entered on the form and the female was assigned to group 1, the second mated female was assigned to group 2, and the third to group 3, etc. This process was continued daily until 25 females were placed into each group.
- Other: International guidelines recognize the efficacy of oral administration.

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: All rats were observed twice daily for moribundity and mortality.
- Cage side observations checked in table [No.?] were included.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Detailed clinical observations were recorded individually from days 0 through 20 of gestation (prior to compound administration during the dosing period). On the first day of test material administration for this study, animals were observed for signs of toxicity approximately one, two and four hours following dosing. Few post-dosing clinical signs were observed two and four hours following dosing; therefore, only a one-hour post-dosing observation was scheduled for the remainder of the test material administration period.

BODY WEIGHT: Yes
- Time schedule for examinations: Individual maternal body weights for all females were recorded on gestation days 0, 6-16 and 20.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Yes (Individual food consumption was recorded on gestation days 0, 6-16 and 20.)
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes (Food intake was reported as g/animal/day and g/kg/day for each corresponding body weight change interval.)
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: No (Compound was administered via gavage)

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No
- Time schedule for examinations: N/A

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day # 20: animals were euthanized by carbon dioxide inhalation. Fetuses were removed by Caesarean section.
- Organs examined: Emphasis on the uterus and its contents, number and position of the fetuses in the uterus, early and late resorptions and the total number of implantation sites.
- Specimens of abnormal tissue were fixed in 10% neutral buffered formalin.

OTHER: Uteri with no macroscopic evidence of nidation were excised, opened and subsequently placed in 10% ammonium sulfide for detection of early implantation loss.

Ovaries and uterine content:

The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: Yes
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes
- Other:

Fetal examinations:

- External examinations: Yes: all per litter;
sex, detailed external examination of each fetus included eyes, palate and external orifices and each fmding was recorded.
crown-rump measurements and any external malformations were recorded for late resorptions
- Soft tissue examinations: Yes: all per litter
- each fetus was examined viscerally by the Wilson sectioning technique; sections containing malformations were preserved in 10% neutral buffered formalin, all remaining serial sections were discarded
-examination of kidneys, grading for renal papillae development

- Skeletal examinations: Yes: all per litter
- Head examinations: Yes: all per litter; The heads from all of the fetuses were examined by a mid-coronal slice.

Statistics:

All analyses were conducted using two-tailed tests for a minimum significance level of 5% comparing each treated group to the vehicle control group.
Chi-square test with Yates correction factor - fetal sex ratios
Fisher's Exact test - malformations and variations
Mann-Whitney U-test - early and late resorptions, dead fetuses, post-implantation losses, mean litter proportions of malformations and variations
One-way ANOVA with Dunnett's test - corpora lutea, total implantations, viable fetuses, fetal body weights, maternal body weights, weight changes, gravid
uterine weights and maternal food consumption
Kruskal-Wallis test - litter proportions of intrauterine data (considering the litter, rather than the fetus, as the experimental unit)

Indices:

fetal sex ratios
malformations and variations
early and late resorptions
dead fetuses
post-implantation losses
mean litter proportions of malformations and variations
corpora lutea
total implantations
viable fetuses
fetal body weights
maternal body weights
weight changes
gravid uterine weights
maternal food consumption
litter proportions of intrauterine data (considering the litter, rather than the fetus, as the experimental unit)

Historical control data:

yes (for embryotoxic effects)

Details on maternal toxic effects:

Maternal toxic effects:no effects. Remark: no treatment related effects

Details on maternal toxic effects:
CUNlCAL OBSERVATIONS AND SURYIVAL No mortality. The predominant clinical sign in the treated groups was rales, which generally did not persist past one hour following dosing. In the 180.5 and 361 mg/kg/day groups, rales were observed in 17 and 16 animals, respectively, on one to five occasions one hour following dosing. Other clinical signs in the treated groups occurred infrequently (generally in single animals) and/or were observed similarly in the control group. BODY WEIGHTS AND GRAYID UTERINE WEIGHTS Mean gravid uterine weight, net body weight and net body weight gain in the highest dose group were slightly lower than the control group values. None of the differences were statistieally significant. Mean body weights, body weight gains, gravid uterine weights, net body weights and net body weight gains in the 36.1 and 180.5 mg/kg/day groups were comparable to the control group values. FOOD CONSUMPTION Food consumption, evaluated as g/animal/day and g/kg/day, in the 36.1, 180.5 and 361 mg (a.i.)/kg/day groups was unaffected by compound administration. The only statistically significant difference (p <0.01) between the control and treated groups was a slightly lower g/animall/day food consumption value in the 361 mg/kg/day group during the post-treatment period (gestation days 16-20). The difference between the control and high dose groups was slight (2 g/animal/day) and no relationship to treatment was apparent. NECROPSY DATA At the scheduled necropsy, no internal findings related to compound administration were observed at any dose level. GESTATION DAY 20 LAPAROHYSTERECTOMY DATA Intrauterine growth and survival were unaffected by compound administration at any dose level. Postimplantation losses in the treated groups were comparable to the control group value. The mean numbers of viable fetuses in the treated groups were also comparable to the control group value with one exception. The mean number of viable fetuses in the 361 mg/kg/day group (12.3 fetuses/dam) was slightly lower than the control group value (13.9 fetuses/dam). The low number of viable fetuses in the high dose group was due to lower mean numbers of corpora lutea and implantation sites in the 361 mg/kg/day group (15.9 corpora lutea/dam and 13.1 implantation sites/dam) than in the control group (17.5 corpora lutea/dam and 14.7 implantation sites/dam). As the numbers of corpora lutea and implantation sites are inherently determined prior to the initiation of dosing, no relationship to treatment was evident. The mean numbers of corpora lutea and implantation sites in the 36.1 and 180.5 mg/kg/day groups were comparable to the control group values. Mean fetal body weights and fetal sex ratios in all treated groups were comparable to the control group values. None of the differences between the control and treated groups were statistically significant.

Dose descriptor:

NOEL

Effect level:

36.1 mg/kg bw/day

Based on:

act. ingr.

Basis for effect level:

other: maternal toxicity

Dose descriptor:

NOAEL

Effect level:

361 mg/kg bw/day

Based on:

act. ingr.

Basis for effect level:

other: maternal toxicity

Dose descriptor:

NOEL

Effect level:

361 mg/kg bw/day

Based on:

act. ingr.

Basis for effect level:

other: developmental toxicity

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effects. Remark: no treatment related effects

Details on embryotoxic / teratogenic effects:
The numbers of fetuses (litters) available for fetal morphological examination were 305(22), 266(19), 330(23) and 271(22) in the control, 36.1, 180.5 and 361 mg/kg/day groups, respectively. The number of fetuses (litters) with malformations were 1(1), 1(1), 1(1), 0(0) in these dose groups, respectively. EXTERNAL MALFORMATIONS AND VARIATIONS one fetus in the 180.5 mg/kg/day group had multiple anomalies. These consisted of craniorachischisis, facial cleft, microphthalmia (unilateral) and ablepharia (bilateral). No other external malformations and no external developmental variations were observed at any dose level. VISCERAL MALFORMATIONS AND VARIATIONS One fetus in the control group had an encephalomeningocele (portion of brain and meninges protruded through an opening in the skull). One fetus in the 36.1 mg/kg bw/day group was hydrocephalic. No other soft tissue malformations were observed at any dose level. Soft tissue developmental variations were observed in two control group fetuses. Both fetuses had renal papillae that were not developed and one fetus also had a distended ureter. No other soft tissue developmental variations were noted. SKELETAL MALFORMATIONS AND VARIATIONS One fetus in 180.5 mg/kg/day group had multiple external skeletal malformations and (external: craniorachischisis, facial cleft, unilateral microphthalmia and bilateral ablepharia; skeletal malformations: malformed clavicle and scapula and a vertebral anomaly with an associated rib anomaly). Skeletal developmental variations in all treated groups, such as cervical centrum no. 1 ossified, sternebrae nos. 5 and/or 6 unossified and 14th rudimentary ribs, occurred at a similar frequency in the control group, did not occur in a dose related manner and/or were within the range of historical control data. All other skeletal variants occurred infrequently (generally in single fetuses) or occurred similarly in the control group.

Dose descriptor:

NOEL

Effect level:

361 mg/kg bw/day

Based on:

act. ingr.

Basis for effect level:

other: embryotoxicity

Dose descriptor:

NOEL

Effect level:

361 mg/kg bw/day

Based on:

act. ingr.

Basis for effect level:

other: fetotoxicity

Dose descriptor:

NOEL

Effect level:

361 mg/kg bw/day

Based on:

act. ingr.

Basis for effect level:

other: teratogenicity

Abnormalities:

not specified

Developmental effects observed:

not specified

CLINlCAL OBSERVATIONS AND SURYIVAL

All animals survived to the scheduled necropsy on gestation day 20. The predominant clinical sign in the treated groups was rales. In the 180.5 and 361 mg/kg/day groups, rales were observed in 17 and 16 animals, respectively, on one to five occasions one hour following dosing between gestation days 6 and 15.

Based on findings two and four hours following dosing on the initial day of compound administration, rales generally did not persist past one hour following dosing. Several animals in the 180.5 and 361 mg/kg/day groups (6 and 2, respectively) were also noted to have rales at the daily examinations prior to dosing. Rales were also observed on one occasion in a single 36.1 mg/kg/day group animal (one hour following dosing on gestation day 8). However, the single occurrence of rales at a dose level of 36.1 mg/kg/day was not suggestive of a relationship to compound administration.

Other clinical signs in the treated groups, such as hair loss on various body surfaces, red material around the nose and soft stool, occurred infrequently (generally in single animals) and/or were observed similarly in the control group. No relationship to compound administration was evident.

BODY WEIGHTS AND GRAVID UTERINE WEIGHTS

Mean body weight gains in the 361 mg/kg/day group were comparable to the control group values during the first six days of dosing (gestation days 6-9 and 9-12).

Throughout the remainder of the treatment period (gestation days 12-16), mean body weight gain in this group was slightly reduced when compared to the control group value. The difference was not statistically significant. When the overall treatment period was evaluated (gestation days 6-16), a statistically significant (P<0.05) reduced mean body weight gain occurred in the 361 mg/kg/day group when compared to the control group value. During the post-treatment period (gestation days 16-20), mean body weight gain in the 361 mg/kg/day group continued to be slightly lower than the control group value. The difference was not statistically significant. Mean body weights in the 361 mg/kg/day group were similar to the control group values throughout the study. Mean gravid uterine weight, net body weight and net body weight gain in this group were slightly lower than the control group values. None of the differences were statistically significant. Mean body weights, body weight gains, gravid uterine weights, net body weights and net body weight gains in the 36.1 and 180.5 mg/kg/day groups were comparable to the control group values.

FOOD CONSUMPTION

Food consumption, evaluated as g/animal/day and g/kg/day, in the 36.1, 180.5 and 361 mg/kg/day groups was unaffected by compound administration. The only statistically significant difference (p <0.01) between the control and treated groups was a slightly lower g/animal/day food consumption value in the 361 mg/kg/day group during the post-treatment period (gestation days 16-20). The difference between the control and high dose groups was slight (2 g/animal/day) and no relationship to treatment was apparent.

NECROPSY DATA

At the scheduled necropsy, no internal findings related to compound administration were observed at any dose level. One female in each of the control and 180.5 mg/kg/day groups (nos. 20671 and 20570, respectively) had dilated renal pelves. The 180.5 mg/kg/day group female (no. 20566) also had enlarged placentas at site nos. 7 and 12. Female no. 20656 in the 36.1 mg/kg/day group had reddened cortieo-medullary junctions in the kidneys. Control group female no. 20593 had a thickened urinary bladder containing one white calculus. All other animals were internally normal.

GESTATION DAY 20 LAPAROHYSTERECTOMY DATA

Intrauterine growth and survival were unaffected by compound administration at any dose level. Postimplantation losses in the treated groups were comparable to the control group value. The mean numbers of viable fetuses in the treated groups were also comparable to the control group value with one exception. The mean number of viable fetuses in the 361 mg/kg/day group (12.3 fetuses/dam) was slightly lower than the control group value (13.9 fetuses/dam). The low number of viable fetuses in the high dose group was due to lower mean numbers of corpora lutea and implantation sites in the 361 mg/kg/day group (15.9 corpora lutea/dam and 13.1 implantation sites/dam) than in the control group (17.5 corpora lutea/dam and 14.7 implantation sites/dam). As the numbers of corpora lutea and implantation sites are inherently determined prior to the initiation of dosing, no relationship to treatment was evident. The mean numbers of corpora lutea and implantation sites in the 36.1 and 180.5 mg/kg/day groups were comparable to the control group values. Mean fetal body weights and fetal sex ratios in all treated groups were comparable to the control group values. None of the differences between the control and treated groups were statistically significant.

FETAL MORPHOLOGICAL DATA

The numbers of fetuses (litters) available for fetal morphological examination were 305(22), 266(19), 330(23) and 271(22) in the control, 36.1, 180.5 and 361 mg/kg/day groups, respectively. The number of fetuses (litters) with malformations were 1(1), 1(1), 1(1), 0(0) in these same dose groups, respectively.

EXTERNAL MALFORMATIONS AND VARIATIONS

At the external examination, one fetus in the 180.5 mg/kg/day group (no. 20652-19) had multiple anomalies. These consisted of craniorachischisis, facial cleft, microphthalmia (unilateral) and ablepharia (bilateral). No other external malformations and no external developmental variations were observed at any dose level.

VISCERAL MALFORMATIONS AND VARIATIONS

Upon soft tissue examination, fetus no. 20661-7 in the 36.1 mg/kg/day group was hydrocephalic. The anomaly consisted of increased cavitation of the lateral and third ventricles. Control group fetus no. 20543-6 was observed with an encephalomeningocele (portion of brain and meninges protruded through an opening in the skull). No other soft tissue malformations were observed at any dose level.

Soft tissue developmental variations were observed in two control group fetuses (nos. 20655-10 and 20662-4). Both fetuses had renal papillae that were not developed and fetus no. 20662-4 also had a distended ureter. No other soft tissue developmental variations were noted.

SKELETAL MALFORMATIONS AND VARIATIONS

Multiple skeletal malformations were observed in a single fetus (no. 20652-19) in the 180.5 mg/kg/day group. This was the same fetus in which multiple malformations were noted at the external examination. The skeletal malformations consisted of a malformed clavicle and scapula and a vertebral anomaly with an associated rib anomaly (vertebral arches and/or ribs fused, extra, thickened or absent). No other skeletal malformations were observed at any dose level.

Skeletal developmental variations in all treated groups, such as cervical centrum no. I ossified, sternebrae nos. 5 and/or 6 unossified and 14th rudimentary ribs, occurred at a similar frequency in the control group, did not occur in a dose related manner and/or were within the range of the WIL historical control data. All other skeletal variants occurred infrequently (generally in single fetuses) or occurred similarly in the control group.

SUMMARY OFEXTERNAL. VISCERAL AND SKELETAL EXAMINATIONS

Fetal external, soft tissue, and skeletal malformations were observed in 1(1), 1(1), 1(1) and 0(0) fetuses (litters) in the control, 36.1, 180.5 and 361 mg/kg/day groups, respectively, and were considered to be spontaneous in ongm. No treatment related trends were apparent when either the actual numbers of malformations were compared or when the specific types of anomalies expressed were considered. None of the values in the treated groups were statistically significant when compared to the control group values. Fetal developmental variations in the treated groups were observed at a frequency similar to that in the control group, occurred infrequently or were within the range of the WILL historical control data.

Conclusions:

In this study administration of Phosphoric acid, C9-15 branched and linear alkyl esters, potassium salts to 25 female Sprague-Dawley Crl:CD® BR rats/dose by oral gavage from day 6 through 15 of gestation had no compound related effects up to and including the highest tested dose of 361 mg/kg/day (active ingredient). Intrauterine growth and survival were unaffected by treatment at any dose level. The fetal malformations observed in this study were all considered to be spontaneous in origin. No treatment-related fetal developmental variations were observed at any dose level.

Executive summary:

In a developmental toxicity study according to OECD guideline 414, Phosphoric acid, C9-15 branched and linear alkyl esters, potassium salts (36.1% a.i.) was administered to 25 female Sprague-Dawley Crl:CD® BR rats/dose by oral gavage at dose levels of 0 (control), 36.1, 180.5 and 361 mg/kg bw/day (active ingredient) from day 6 through 15 of gestation. Females were sacrificed on day 21 post coitum and the fetuses were removed by Caesarean section.

No treatment-related effects on mortality, number of abortions, clinical signs, food consumption, gross pathology, intrauterine growth and survival (incl. postimplantation loss, viable litter size, mean fetal body weights, fetal sex ratios, mean numbers of corpora lutea and implantation sites) were observed.

No treatment-related fetal malformations or fetal developmental variations were observed at any dose level.

The NOEL for maternal toxicity is 36.1 mg/kg bw/day.

The NO(A)EL for maternal toxicity is 361 mg/kg bw/day (highest dose administered).

The NOEL for developmental toxicity is 361 mg/kg bw/day (highest dose administered).

The NOEL for embryotoxicity is 361 mg/kg bw/day (highest dose administered).

The NOEL for fetotoxicity is 361 mg/kg bw/day (highest dose administered).

The NOEL for teratogenicity is 361 mg/kg bw/day (highest dose administered).

The developmental toxicity study in the rat is classified acceptable and satisfies the guideline requirement for a developmental toxicity study (OECD 414) in rat.

Effect on developmental toxicity: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

316 mg/kg bw/day

Study duration:

subchronic

Species:

rat

Quality of whole database:

The key study is of high quality with Klimisch score = 1; the reliability was changed from RL1 to RL2 to reflect the fact that this study was conducted on a read-across substance.

Effect on developmental toxicity: via inhalation route

Endpoint conclusion:

no study available

Effect on developmental toxicity: via dermal route

Endpoint conclusion:

no study available

Additional information

Reliable, relevant and adequate data on prenatal developmental toxicity are available for the read-across substance Phosphoric acid, C9-15 branched and linear alkyl esters, potassium salts.

The read-across approach is appropriate due to similar composition of source substance and registered substance. From the available data is can be concluded that the repeated dose toxicity of substances with different alkyl moieties (C12, C14, C9-15 linear and branched) is comparable.

Phosphoric acid alkyl esters are hydrolysed unspecifically by phosphatases, e.g. acid phosphatase or alkaline phosphatase. Both enzymes are found in most organisms from bacteria to human. Alkaline phosphatases are present in all tissues, but are particularly concentrated in liver, kidney, bile duct, bone, placenta. In human and most other mammals three isoenzymes of Alkaline phosphatase exist: intestinal ALP, placental ALP, tissue non-specific ALP (present in bone, liver, kidney, skin).

Seven different forms of Acid phosphatase are known in humans and other mammals. These are also present in different tissues and organs (predominantly erythrocytes, liver, placenta, prostate, lung, pancreas).

Linear and branched primary aliphatic alcohols are oxidised to the corresponding carboxylic acid, with the corresponding aldehyde as a transient intermediate. The carboxylic acids are further degraded via acyl-CoA intermediates in by the mitochondrial beta-oxidation process. Branched aliphatic chains can be degraded via alpha- or omega-oxidation (see common text book on biochemistry).

“The long chain aliphatic carboxylic acids are efficiently eliminated and aliphatic alcohols are therefore not expected to have a tissue retention or bioaccumulation potential (Bevan, 2001).

Longer chained aliphatic alcohols within this category may enter common lipid biosynthesis pathways and will be indistinguishable from the lipids derived from other sources (including dietary glycerides) (Kabir, 1993; 1995a,b).

A comparison of the linear and branched aliphatic alcohols shows a high degree of similarity in biotransformation. For both sub-categories the first step of the biotransformation consists of an oxidation of the alcohol to the corresponding carboxylic acids, followed by a stepwise elimination of C2 units in the mitochondrial β-oxidation process. The metabolic breakdown for both the linear and mono-branched alcohols is highly efficient and involves processes for both sub-groups of alcohols. The presence of a side chain does not terminate the β-oxidation process, however in some cases a single Carbon unit is removed before the C2 elimination can proceed.” (OECD SIDS, 2006).

The Phosphoric acid alkyl esters with branched fatty alcohol chains can be considered as a worst case scenario because the metabolism of the resulting branched fatty acids occurs less efficient compared to linear fatty acids.

 

Thus, it can be expected, that also the effects on development of the Phosphoric acid C9-15, branched and linear alkyl ester will be similar to those of Phosphoric acid, mono- and di- C16-18 (even numbered) alkyl esters.

 

In a developmental toxicity study according to OECD guideline 414, Phosphoric acid, C9-15 branched and linear alkyl esters, potassium salts (36.1% a.i.) was administered to 25 female Sprague-Dawley Crl:CD® BR rats/dose by oral gavage at dose levels of 0 (control), 36.1, 180.5 and 361 mg/kg bw/d (active ingredient) from day 6 through 15 of gestation. Females were sacrificed on day 21 post coitum and the fetuses were removed by Caesarean section.

No treatment-related effects on mortality, number of abortions, clinical signs, food consumption, gross pathology, intrauterine growth and survival (incl. postimplantation loss, viable litter size, mean fetal body weights, fetal sex ratios, mean numbers of corpora lutea and implantation sites) were observed.

No treatment-related fetal malformations or fetal developmental variations were observed at any dose level.

The NOEL for maternal toxicity is 36.1 mg/kg bw/d.

The NO(A)EL for maternal toxicity is 361 mg/kg bw/d (highest dose administered).

The NOEL for developmental toxicity is 361 mg/kg bw/d (highest dose administered).

The NOEL for embryotoxicity is 361 mg/kg bw/d (highest dose administered).

The NOEL for fetotoxicity is 361 mg/kg bw/d (highest dose administered).

The NOEL for teratogenicity is 361 mg/kg bw/d (highest dose administered).

There is no data gap in prenatal developmental toxicity. There is no reason to believe that results of the prenatal developmental toxicity study would not be relevant for developmental toxicity in humans and, therefore, for risk assessment.

 

Justification for selection of Effect on developmental toxicity: via oral route:

OECD guideline study, GLP

Justification for classification or non-classification

In conclusion, the results of the available data on toxicity to reproduction, developmental toxicity and teratogenicity indicate that Phosphoric acid, C16-18-alkyl esters, potassium salts do not need to be classified for toxicity to reproduction (fertility), developmental toxicity and teratogenicity according to Directive 67/548/EEC as well as CLP, EU GHS (Regulation 1272/2008/EC) and therefore labelling is not necessary.