1-Propanaminium, 3-amino-N-(carboxymethyl)-N,N-dimethyl-, N-(C8-18(even numbered) and C18 unsaturated acyl) derivs., hydroxides, inner salts

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Description of key information

From the 28-day and 90-day repeated oral dose toxicity studies and developmental toxicity studies in rats there are no indications of any substance-related effects on reproductive organs up to including the highest tested doses of 300 and 1000 mg a.i./kg bw/day, respectively.

Effect on fertility: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

300 mg/kg bw/day

Study duration:

subchronic

Species:

rat

Quality of whole database:

OECD guideline studies, RL1, GLP

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 data repeated dose toxicity studies (28 d and 90 d studies) in rats with additional focus on reproductive organs are available for C8-18 and C18 unsatd. AAPB (Coco AAPB).

Further data are available from a 90 d repeated dose toxicity study as well as a prenatal developmental toxicity study in rats conducted with the closely related C8-18 AAPB.

A justification for read-across is given below.

 

In the 28-day and 90-day repeated dose toxicity studies (tested doses up to and including approximately 300 mg a.i./kg bw/d) and developmental toxicity study (tested doses up to and including 1000 mg a.i./kg bw/d) in rats, there were no histopathological changes in reproductive organs (seminal vesicles, prostate, epididymides, testes, mammary glands, ovaries and fallopian tubes, uterus, cervix, vagina) and no effects on reproductive organs weights (testes, ovaries). In the prenatal developmental toxicity study AAPBs showed no teratogenic activity, and embryotoxic effects were found only at the maternal toxic dose level. Taking into account the overall low toxic activity of the AAPBs, particularly with regard to the missing adverse effects on reproductive organs or tissues in the 28-day and 90-day studies as well as in the developmental toxicity study, the missing teratogenic activity, the fact that embryotoxic effects were found only at the maternal toxic dose level and the toxicodynamics of AAPBs, which is primarily based on its irritancy, fertility-specific effects are highly unlikely to occur. Therefore, further reproductive toxicity studies do not need to be conducted.

 

In accordance with Annex X column 2 of the REACH Regulation (EC) No 1907/2006, the performance of a two-generation reproductive toxicity study is not required. AAPB is of low systemic toxicity as indicated by a LD50> 2000 mg/kg bw. No indication of any systemic toxicity of AAPBs relevant in view of a potential health risk for humans was found in the sub-chronic toxicity studies, including reproductive organs. From developmental toxicity data, there is no evidence for teratogenic effects. AAPBs have no genotoxic properties as proven in the full data set includingin vivodata.

The use profile of the substance indicates that relevant exposure to humans occurs via the dermal route. Reliable, relevant and adequate toxicokinetic data from anin vitrostudy on human skin showed a dermal resorption rate of 0%.

 

Based on the above specified toxicological and toxicokinetic data, it can be proven that the substance is of low toxicological activity and that no systemic absorption occurs via the relevant route of exposure. Therefore, further reproductive toxicity studies do not need to be conducted.

Further, in accordance with Annex XI, section 1.2 of the REACH Regulation (EC) No 1907/2006, the performance of a two-generation reproductive toxicity study is scientifically unjustified. As indicated above there is no indication of any systemic toxicity of AAPBs relevant in view of a potential health risk for humans, neither from sub-chronic data nor from developmental toxicity data.

In conclusion, further testing on vertebrate animals in a 2-generation reproductive toxicity study or extended one generation reproductive toxicity study is unjustified.

 

Conclusion

The NOEL for effects on fertility is derived from the 90 d repeated dose toxicity study with additional focus on reproductive organs, which was conducted with C8-18 AAPB which is the highest tested dose of 300 mg a.i./kg bw/day (= 1000 mg product (a.i. ca. 30%)/kg bw/day.

 

There are no data gaps for the endpoint fertility. No human data are available. However, there is no reason to believe that these results from rabbit would not be applicable to humans.

 

Justification for read-across

For details on substance identity and detailed toxicological profiles, please refer also to the general justification for read-across attached as pdf document to IUCLID section 13.

This read-across approach is justified based on structural similarities. All AAPBs contain the same functional groups. Thus a common mode of action can be assumed.

The only deviation within this group of substances is a minor variety in their fatty acid moiety (chain length and degree of unsaturation), which may have an influence on the outcome of skin and eye irritation studies, but is not expected to have any influence on systemic or reproductive toxicity.

 

a. Structural similarity and functional groups

Alkylamidopropyl betaines (AAPBs) are – with the exception of C12 AAPB - UVCB substances (Substances of Unknown or Variable composition, Complex reaction products or Biological materials), which are defined as reaction products of natural fatty acids or oils with dimethylaminopropylamine and further reaction with sodium monochloroacetate. AAPBs are amphoteric surfactants, which are characterized by both acidic and alkaline properties.

 

Their general structure is:

 

R-C(O)-NH-(CH₂)₃-(N(CH₃)₂)⁺-CH₂-C(O)O^-

R = fatty acid moiety

 

The fatty acids have a mixed, slightly varying composition with an even numbered chain length from C8 to C18. Unsaturated C18 may be included. Consequently, the AAPBs differ by their carbon chain length distribution and the degree of unsaturation in the fatty acid moiety. However, Lauramidopropyl betaine (C12 fatty acid derivate) is the major ingredient of all AAPBs covered by this justification as listed in table 1 “Substance identities” of the general justification for read-across.

 

The substances under evaluation share structural similarities with common functional groups (quaternary amines, amide bonds and carboxymethyl groups), and fatty acid chains with differences in chain length and degree of saturation.

 

b. Differences

Differences in reproductive toxicity of the AAPBs could potentially arise from the following facts:

-Different amounts of different carbon chain lengths (carbon chain length distribution):

Higher amounts of higher chain lengths and corresponding lower amounts of lower chain length could result in a rising average lipophilicity.The variability in fatty acid chain length is not expected to have any influence on thesystemic or reproductive toxicityof the AAPBs

- Different amounts of unsaturated fatty ester moieties:

Effects may be expected for e.g. physical state and for some toxicological endpoints, mainly local effects (e.g. irritation). The variability in the degree of unsaturation is not expected to have any influence on the systemic or reproductive toxicity of the AAPBs.

 

Comparison of reproductive toxicity data

 

Endpoints	Source substance	Target substance
	C8-18 AAPB	C8-18 and C18 unsatd. AAPB
Repeated dose toxicity, oral	Key_gavage_Repeated dose toxicity: oral: 97862-59-4_ 8.6.2_Goldschmidt_1991_OECD 408 key study OECD TG 408, subchronic, rat, oral: gavage NOEL systemic effects: 300 mg a.i./kg bw/d (highest tested dose, 1000 mg/kg bw/d based on product (a.i. ca. 30 %)) LOEL local effects: 150 mg a.i./kg bw/d (500 mg/kg bw/d based on product (a.i. ca. 30 %)) NOEL local effects: 75 mg a.i./kg bw/d (250 mg/kg bw/d based on product (a.i. ca. 30 %))   Reliability: 1 (reliable without restriction), GLP	Key_feeding_Repeated dose toxicity: 61789-40-0_8.6.2_90days_Unilever_A03_FT890785   Key study   OECD TG 408, subchronic, rat, oral: feed   NOEL effects relevant to humans: 247 mg a.i./kg bw/d (highest tested dose, 1 % in feed, 731 mg/kg bw/d based on product (a.i. 33.8 %))   LOEL: 97 mg a.i./kg bw/day) (0.4% in feed, 288 mg/kg bw/d based on product (a.i. 33.8 %))   Reliability: 1 (reliable without restriction), GLP
		Sup_Repeated dose toxicity: oral: 61789-40-0_8.6.1_Henkel_1991_OECD 407   Supporting study OECD TG 407, subacute, rat, oral: gavage NOEL systemic effects 300 mg a.i./kg bw/d (highest tested dose, 1000 mg/kg bw/d based on product (a.i. 30 %)) LOAEL local effects 300 mg a.i./kg bw/d (highest tested dose, 1000 mg/kg bw/d based on product (a.i. 30 %)) NOEL local effects 150 mg a.i./kg bw/d (500 mg/kg bw/d based on product ( a.i. 30%))   Reliability: 1 (reliable without restriction), GLP
Prenatal developmental toxicity	Key_Developmental toxicity / teratogenicity: 97862-59-4_8.7.2_CESIO_2004_OECD 414 Key study OECD TG 414, rat, oral: gavage NOEL maternal toxicity: 100 mg a.i./kg bw/day NOEL embryotoxicity: 300 mg a.i./kg bw/day NOEL teratogenicity: 1000 mg a.i./kg bw/day Maternal toxic effects: yes Embryotoxic / teratogenic effects: yes   Reliability: 1 (reliable without restriction), GLP	Supporting data (no RSS)   Rat, days 6 through 17 of gestation   NOEL = 300 mg/kg bw/d   Reliability: 4 (not assignable, data insufficient for assessment), no data on GLP

 

In the repeated dose toxicity studies performed according to the corresponding OECD Guidelines on C8-18 AAPB and C8-18 and C18 unsatd. AAPB, up to and including the highest tested dose (300 mg a.i./kg bw/d), no indication of any effects of AAPBs to reproductive organs were observed.

In the prenatal developmental toxicity study (tested doses up to and including 1000 mg a.i./kg bw/d) AAPBs showed no teratogenic activity, and embryotoxic effects were found only at the maternal toxic dose level.

Further supporting data are available for C8-18 and C18 unsatd. AAPB, which were however not of sufficient detail for assessment.

 

Quality of the experimental data of the analogues:

The available data are adequate and sufficiently reliable to justify the read-across approach.

Repeated dose toxicity studies:

Both key studies were conducted according to OECD Guideline 408 and were reliable without restrictions (RL1, GLP). A supporting study conducted according to OECD Guideline 407 (RL1, GLP) is available.

Prenatal developmental toxicity study:

The key study was conducted according to OECD Guideline 414 and was teliable without restrictions (RL1, GLP).

The test materials used in the respective studies represent the source substance as described in the hypothesis in terms of substance identity and minor constituents.

Overall, the study results are adequate for the purpose of classification and labelling and risk assessment.

 

Conclusion

Based on structural similarities of the target and source substancesas presented above and in more detail in the general justification for read across, it can be concluded that the available data from the source substances C8-18 AAPB are also valid for the target substance C8-18 and C18 unsatd. AAPB.

In therepeated dose toxicity studies in rats conducted with C8-18 and C18 unsatd. AAPB and C8-18 AAPB, there were no histopathological changes in reproductive organs (seminal vesicles, prostate, epididymides, testes, mammary glands, ovaries and fallopian tubes, uterus, cervix, vagina) and no effects on reproductive organs weights (testes, ovaries).

Taking into account the overall low toxic activity of the AAPBs, particularly with regard to the missing adverse effects on reproductive organs or tissues in the 28-day and 90-day studies as well as in the developmental toxicity study, the missing teratogenic activity, the fact that embryotoxic effects were found only at the maternal toxic dose level and the toxicodynamic of AAPBs, which is primarily based on its irritancy, fertility-specific effects are highly unlikely.

Effects on developmental toxicity

Description of key information

A relevant, reliable and adequate developmental toxicity / teratogenicity study on C8-18 AAPB is available. In this study, performed according to OECD TG 414 on CD rats, 330, 990 and 3300 mg/kg bw/day of a 28.9 % aqueous solution of C8-18 AAPB, corresponding to 100, 300, and 1000 mg active substance/kg bw/day, respectively, were applied by gavage. Dose-related maternal toxic effects (reduced food consumption, impaired body weight and necropsy stomach findings) occurred at 990 mg/kg bw/day and above. Embryotoxic effects (reduced mean fetal weight and increased number of resorptions) were found only at the maternal toxic dose level of 3300 mg/kg bw/day. Up to and including the highest tested dose, no external, skeletal or soft tissue malformations and no external variations were found. The NOEL for maternal toxicity was 330 mg/kg bw/day (corresponding to 100 mg active substance/kg bw/day) and the NOEL for developmental toxicity was 990 mg/kg bw/day (corresponding to 300 mg active substance/kg bw). The NOEL for teratogenic effects was the highest tested dose of 3300 mg/kg bw/day, corresponding to the guideline limit dose of 1000 mg active ingredient/kg bw/day.

Effect on developmental toxicity: via oral route

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEL

300 mg/kg bw/day

Study duration:

subacute

Species:

rat

Quality of whole database:

OECD guideline study, RL1, GLP

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

No sufficiently reliable experimental data on effects on developmental toxicity are available for C8-18 and C18 unsatd. AAPB (Coco AAPB). However, reliable data from a prenatal developmental toxicity study in rats conducted with C8-18 AAPB are available.

A justification for read-across is given below.

 

In a prenatal developmental toxicity study performed according OECD 414, C8-18 AAPB (28.9% a.i, 62% water, and 5.4% NaCl) was administered to 25 females CD rats/dose at dose levels of 0, 330, 990, 3300 mg from day 5 through 19 of gestation by gavage. The test item dose levels refer to nominal active ingredient of 100, 300, and 1000 mg/kg bw/day. The nominal values were analytically verified in samples taken at study initiation and study termination. The actual concentrations of the samples taken from the aqueous test item carrier mixtures were within the range of 101.9 % to 109.9 % of the nominal C8-18 AAPB concentrations indicating correctly prepared application mixtures and a sufficient stability. Number of evaluated pregnant rats were 20/group (the first 20 animals with pregnancy signs were used). Animals evaluated for maternal toxicity were 20/group except of high dose group in which one additional animal was included due to a premature death of one dam.

Regarding maternal toxicity, the dams of the 990 mg/kg bw/day group showed decreased net body weight change from day 6 onward (= carcass weight minus day 6 body weight), reduced food consumption, thickened/partly thickened stomach mucosa in 4 of 20 animals and in addition ulcers (diameter approximately 1 mm or 0.5 to 1 mm) in 2/4 animals with thickened mucosa. In the 3300 mg/kg bw/day group the dams showed severely reduced food consumption, reduced body weights (absolute, body weight gain on gestation days 3 to 6, 6 to 9, 12 to 15, 15 to 18 and 18 to 20, and net body weight change from day 6 onward), reduced carcass weight and reduced gravid uterus weights. Thickened or partly thickened stomach mucosa (greyish discoloured in two dams) was noted in 20 of 21 dams including one prematurely deceased dam. In addition, in two of these dams a few ulcers were noted in the stomach (diameter up to 1 mm).

The number of early, late and total resorptions was increased in the 3300 mg/kg bw/day group, and the ratio of viable fetuses to implantation sites was decreased compared to the controls. This was due to a total post-implantation loss in two dams in this dose group. In addition, a statistically significant reduction in fetal weights and in the number of viable fetuses as compared to the control was observed. No external, skeletal or soft tissue malformations and no external variations were found.

The NOEL for maternal toxicity was 330 mg/kg bw/day (corresponding to 100 mg active ingredient/kg bw/day).

The NOEL for developmental toxicity was 990 mg/kg bw/day (corresponding to 300 mg active ingredient/kg bw/day).

The NOEL for external, skeletal or soft tissue malformations and variations was the highest tested dose of 3300 mg/kb bw/day (corresponding to the guideline limit dose of 1000 mg active ingredient/kg bw/day.

 

In HERA risk assessment report first edition, 2005 an additional developmental toxicity study is reported as follows: “One further developmental toxicity study is available with cocamidopropyl betaine (30% active substance). Female pregnant rats were administered 0, 30, 90 or 300 mg/kg bw on days 6 through 17 of gestation. No treatment-related effects on the incidence of fetal external, visceral, or skeletal malformations or developmental variations were observed among litters from dams in any of the treated groups.

The maternal and developmental no-observed-effect level (NOEL) of this study was 300 mg/kg bw/d, the highest level (Colgate-Palmolive, 2000).”

 

There are no data gaps for the endpoint developmental toxicity. No human data are available. However, there is no reason to believe that these results from rabbit would not be applicable to humans.

 

Justification for read-across

For details on substance identity and detailed toxicological profiles, please refer also to the general justification for read-across attached as pdf document to IUCLID section 13.

This read-across approach is justified based on structural similarities. All AAPBs contain the same functional groups. Thus a common mode of action can be assumed.

The only deviation within this group of substances is a minor variety in their fatty acid moiety (chain length and degree of unsaturation), which may have an influence on the outcome of skin and eye irritation studies, but is not expected to have any influence on developmental toxicity.

 

a. Structural similarity and functional groups

Alkylamidopropyl betaines (AAPBs) are – with the exception of C12 AAPB - UVCB substances (Substances of Unknown or Variable composition, Complex reaction products or Biological materials), which are defined as reaction products of natural fatty acids or oils with dimethylaminopropylamine and further reaction with sodium monochloroacetate. AAPBs are amphoteric surfactants, which are characterized by both acidic and alkaline properties.

 

Their general structure is:

 

R-C(O)-NH-(CH₂)₃-(N(CH₃)₂)⁺-CH₂-C(O)O^-

R = fatty acid moiety

 

The fatty acids have a mixed, slightly varying composition with an even numbered chain length from C8 to C18. Unsaturated C18 may be included. Consequently, the AAPBs differ by their carbon chain length distribution and the degree of unsaturation in the fatty acid moiety. However, Lauramidopropyl betaine (C12 fatty acid derivate) is the major ingredient of all AAPBs covered by this justification as listed in table 1 “Substance identities” of the general justification for read-across.

 

The substances under evaluation share structural similarities with common functional groups (quaternary amines, amide bonds and carboxymethyl groups), and fatty acid chains with differences in chain length and degree of saturation.

 

b. Differences

Differences in reproductive toxicity of the AAPBs could potentially arise from the following facts:

-Different amounts of different carbon chain lengths (carbon chain length distribution):

Higher amounts of higher chain lengths and corresponding lower amounts of lower chain length could result in a rising average lipophilicity.The variability in fatty acid chain length is not expected to have any influence on thedevelopmental toxicityof the AAPBs

- Different amounts of unsaturated fatty ester moieties:

Effects may be expected for e.g. physical state and for some toxicological endpoints, mainly local effects (e.g. irritation). The variability in the degree of unsaturation is not expected to have any influence on the developmental toxicity of the AAPBs.

 

Comparison of prenatal developmental toxicity data

 

Endpoints	Source substance	Target substance
	C8-18 AAPB	C8-18 and C18 unsatd. AAPB
Prenatal developmental toxicity	Key_Developmental toxicity / teratogenicity: 97862-59-4_8.7.2_CESIO_2004_OECD 414 Key study OECD TG 414, rat, oral: gavage NOEL maternal toxicity: 100 mg a.i./kg bw/day NOEL embryotoxicity: 300 mg a.i./kg bw/day NOEL teratogenicity: 1000 mg a.i./kg bw/day Maternal toxic effects: yes Embryotoxic / teratogenic effects: yes   Reliability: 1 (reliable without restriction), GLP	Supporting data (no RSS)   Rat, days 6 through 17 of gestation   NOEL = 300 mg/kg bw/d   Reliability: 4 (not assignable, data insufficient for assessment), no data on GLP

 

In the prenatal developmental toxicity study (tested doses up to and including 1000 mg a.i./kg bw/d) AAPBs showed no teratogenic activity, and embryotoxic effects were found only at the maternal toxic dose level.

The NOEL for maternal toxicity was 100 mg a.i./kg bw/day based on decreased net body weight change, reduced food consumption, thickened/partly thickened stomach mucosa in 4 of 20 animals and in addition ulcers (diameter approximately 1 mm or 0.5 to 1 mm) in 2/4 animals with thickened mucosa in the 300 mg a.i./kg bw/d dose group..

The NOEL for developmental toxicity was 300 mg a.i./kg bw/day based on an increased number of early, late and total resorptions as well as a decrease in the ratio of viable fetuses to implantation sites, which was due to a total post-implantation loss in two dams in the high dose group.

The NOEL for external, skeletal or soft tissue malformations and variations was the guideline limit dose of 1000 mg a.i./kg bw/day.

Further supporting data are available for C8-18 and C18 unsatd. AAPB, which were however not of sufficient detail for assessment. However, it is reported, that no treatment-related effects on the incidence of fetal external, visceral, or skeletal malformations or developmental variations were observed among litters from dams in any of the treated groups.

 

Quality of the experimental data of the analogues:

The available data are adequate and sufficiently reliable to justify the read-across approach.

The key study was conducted according to OECD Guideline 414 and was reliable without restrictions (RL1, GLP).

The test materials used in the respective studies represent the source substance as described in the hypothesis in terms of substance identity and minor constituents.

Overall, the study results are adequate for the purpose of classification and labelling and risk assessment.

 

Conclusion

Based on structural similarities of the target and source substancesas presented above and in more detail in the general justification for read across, it can be concluded that the available data from the source substance C8-18 AAPB are also valid for the target substance C8-18 and C18 unsatd. AAPB.

The effects on development of the whole group of AAPBs is expected to be in the same range as variability in the fatty acid moiety is not expected to be relevant to the intrinsic systemic toxicity of the compounds.

In the developmental toxicity / teratogenicity study conducted with C8-18 AAPB, the test substance C8-18 AAPB showed no teratogenic activity, and embryotoxic effects were found only at the maternal toxic dose level. 

Justification for classification or non-classification

There is no evidence for an intrinsic toxicity to reproduction of AAPBs from the results of an reliable oral developmental toxicity / teratogenicity study on rats at doses up to and including the guideline limit dose of 1000 mg a. i./kg bw/day and reliable oral subchronic and subacute repeated dose toxicity studies with histopathological examination of the male and female reproductive organs (epididymides, testes, seminal vesicle, prostate, ovaries, fallopian tubes, uterus, vagina, mammary gland).

Therefore no classification is required for toxicity to reproduction according to CLP, EU GHS (Regulation (EC) No 1272/2008) and directive 67/548/EEC.