Fatty acids, tall-oil, manganese salts

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Description of key information

No toxicity data on adverse effects on sexual function and fertility with fatty acids, tall-oil, manganese salts are available, thus the reproductive toxicity will be addressed with existing data on the individual moieties manganese and tallate.

Fatty acids, tall-oil, manganese salts is not expected to show adverse effects on sexual function and fertility, since the two moieties manganese and fatty acids, tall-oil have not shown adverse effects reproduction in relevant high quality animal experiments. Additionally, the moiety fatty acids, tall-oil is obtained from natural sources and excluded from the obligation to register.

Additional information

Read-across approach

Selected endpoints for the human health hazard assessment are addressed by read-across, using a combination of data on the metal cation and the organic acid anion. This way forward is acceptable, since metal carboxylates are shown to dissociate to the organic anion and the metal cation upon dissolution in aqueous media. No indications of complexation or masking of the metal ion through the organic acid were apparent during the water solubility and dissociation tests (please refer to the water solubility and dissociation in sections 4.8 and 4.21 of IUCLID). Once the individual transformation products of the metal carboxylate become bioavailable (i.e. in the acidic environment in the gastric passage or after phagocytosis by pulmonary macrophages), the “overall” toxicity of the dissociated metal carboxylate can be described by a combination of the toxicity of these transformation products, i.e. the metal cation and carboxylate anion according to an additivity approach.

Fatty acids, tall-oil, manganese salts is the manganese metal salt of fatty acids, tall-oil, which readily dissociates to the corresponding divalent manganese cation and tallate anions. The manganese cation and the tallate anions are considered to represent the overall toxicity of Fatty acids, tall-oil, manganese salts in a manner proportionate to the free acid and the metal (represented by one of its readily soluble salts). 

A detailed justification for the read-across approach is added as a separate document in section 13 of IUCLID.

 

Toxicity for reproduction– effects on fertility

No toxicity data on adverse effects on sexual function and fertility with Fatty acids, tall-oil, manganese salts is available, thus the reproductive toxicity will be addressed with existing data on the dissociation products as detailed in the table below. Further details on the reproductive toxicity of the individual constituents are given below.

 

Table: Summary of toxicity data on adverse effects on sexual function and fertility of Fatty acids, tall-oil, manganese salts and the individual constituents.

	Manganese sulfate (CAS# 7785-87-7)	Fatty acids, tall-oil	Fatty acids, tall-oil, manganese salts (CAS# 8030-70-4)
Repeated dose toxicity data	Not adverse effects on reproductive organs observed (chronic study, rat)   NOAEL(rat, male)= 615 mg MnSO4/kg bw/day   NOAEL(rat, male)= 715 mg MnSO4/kg bw/day   NOAEL(rat, male)= 224 mg Mn/kg bw/day   NOAEL(rat, male)= 260 mg Mn/kg bw/day	NOAEL >10,000 mg/kg bw/day	See section on repeated dose toxicity
Two-generation reproductive toxicity study	Not reprotoxic (weight of evidence, animal data) Not classified	No data   Not classified	No data   Not classified

 

Manganese (information taken from IEH, 2004)

In an NTP 2-year feeding study on Fischer 344 rats and B6C3F1 mice, there were no changes in testes weight noted and no effects on the seminiferous vesicles with manganese sulphate fed in the diet at concentrations of up to 15 000 ppm. Histopathological examination performed on mammary gland, ovary, prostate gland, testes/epididymis, and uterus did not reveal any test item-related effects (NTP, 1993).

 

In a study only briefly described, Kar et al. (1972) treated rats with 8 mg manganese chloride (8 mg/kg bw) intraperitoneally, daily. Testicular manganese content was determined together with levels of amino acids after 30 and 60 days. Manganese content of the testes showed a 4- and 9-fold increase respectively and after 60 days there were increases in alanine, cysteine, leucine, proline, phenylalanine and glutamine, as compared to controls. The authors concluded that manganese showed evidence of an effect on metabolism in the testes much earlier than changes in histology.

Laskey et al. (1982) chronically treated Long-Evans rats with manganese (II,III) oxide Mn3O4 beginning on day 1 of gestation up to 224 days of age. The manganese was administered in low or high iron diets at concentrations of 350, 1050 and 3050 ppm. The highest manganese level with low iron was stopped after 40 days as there were 50% fatalities. The highest concentration with sufficient iron in the diet, showed some reduction in fertility and the higher doses showed some minimal effects on male reproductive development as measured by testes weight, sperm count and serum follicle stimulating hormone and testosterone. None of these effects was severe enough to alter functional reproduction.

Laskey et al. (1985) described a study in which Long-Evans rats were dosed orally from birth to 21 days with particulate manganese (II,III) oxide (Mn3O4) at doses of 0, 71 or 214 μg/kg bw/day. Assessments were made of hypothalamic, pituitary and testicular function by the measurement of endogenous and stimulated serum concentrations of the pituitary hormones, luteinising hormone and follicle stimulating hormone, and testosterone after 21 and 28 days. There were no significant dose or time-dependent changes in body or testes weight or in follicle stimulating hormone or luteinising hormone levels. There was a significant reduction in serum testosterone after 7 days of stimulation with human chorionic gonadotropin and the authors suggested that any effect is at the level of the testicular Leydig cell and there are no effects on the hypothalamus or pituitary. The hypothalamic manganese concentration seen in these animals is three times that seen in other studies where alterations in the dopaminergic systems have been reported.

In a further study, male Sprague-Dawley rats were fed manganese sulphate (1000 ppm) in drinking water for 12 weeks and territorial aggression, sexual behaviour and fertility were then investigated. There was a decrease in territorial aggression in the treated rats and some slight effects on sexual behaviour, elongation in the time to ejaculation and post-ejaculation. There were no changes in fertility but an increase was seen in the number of resorptions (Bataineh et al., 1998).

New-born CD-1 mice were chronically exposed to manganese oxide for 58, 73 or 90 days. The control diet contained 50 ppm manganese sulphate while the treated mice were exposed to a further 1050 ppm manganese as manganese (IV) oxide. The mice were tested for reactive locomotor activity and sexual development. While body, liver and kidney weights remained unchanged, the growth of the testes, seminal vesicles and preputial glands were retarded. The activity of the rats in a maze over a 2-hour period was significantly reduced at 73 days (Gray & Laskey, 1980).

Joardar and Sharma (1990) compared the cytogenetic and clastogenetic effects of cationic (manganese sulphate) and anionic (potassium permanganate) salts of manganese in male Swiss mice. The manganese sulphate concentrations used were 610, 205 and 102.5 mg/kg bw and potassium permanganate, 380, 130 and 65 mg/kg bw. These concentrations constituted 1/5, 1/15 and 1/30 of a previously experimentally derived LD50 although no details are given. Among the endpoints measured was sperm-head abnormality in five animals for each treatment, administered orally for 5 days then killed after 35 days; 500 sperm were assessed for each animal. There was a significant trend for increased sperm head abnormalities for both manganese sulphate and potassium permanganate.

Fertility was estimated in male Swiss mice exposed for 12 weeks to 1000, 2000, 4000 or 8000 mg/ℓ manganese chloride in drinking water (Elbetieha et al., 2001). Mice were then mated for 10 days with unexposed females, which were then killed after a further 10 days and the number of pregnant females, implantation sites, viable fetuses and resorptions recorded. Fertility was significantly reduced in males exposed to 8000 mg/ℓ although there were no changes in the other parameters. In a further experiment, female mice were exposed to the same concentrations of manganese chloride for 12 weeks and then mated with unexposed males for 10 days and killed after a further 10 days as before. Fertility was not reduced in any treatment group but the numbers of implantation sites and viable fetuses were significantly reduced in the highest dose group (8000 mg/ℓ).

 

Rabbits were treated with single intratracheal injection of manganese dioxide (250 mg/kg bw) and killed at 4 and 8 months for histological and biochemical analysis. After 8 months, groups of treated and untreated rabbits were also tested for fertility. After 4 months, there were signs of degeneration in about 30% of seminiferous tubules, while at 8 months there was extensive disruption of the tubules with marked degeneration of spermatocytes and spermatids. This was accompanied by infertility.

There were decreased levels of enzymes found in the testes of the treated rabbits — acid phosphatase

(27%), adenosine triphosphatase (38%), succinic dehydrogenase (78%). The authors suggested that manganese affected the energy metabolism in the testes leading to the destruction of sperm producing structures (Chandra et al., 1973b). In a further study by the same group (Imam & Chandra, 1975), male rabbits received daily intravenous injections of 3.5 mg manganese chloride /kg bw for 5, 10, 15 and 30 days before killing. The testes then underwent histological and histochemical analysis. Again, there was a decrease in succinic dehydrogenase and a decrease in glucose-6-phosphate dehydrogenase in the seminiferous tubules with increasing degeneration from day 5 onward.

Huang et al. (2001) showed that manganese nitrate inhibited sperm motility in vitro at a concentration of 500 ppm. However, there was no evidence of accompanying lipid peroxidation, measured by the production of malondialdehyde and indicative of free radical damage. The authors concluded that this effect on sperm motility at high concentration was not biologically or environmentally relevant.

 

A number of studies in rats, mice and rabbits suggest that manganese has an adverse effect on male reproductive organs and fertility.

However, the results from the best reported study, that of a 2-year study in rats and mice (NTP, 1993), indicated no change in testes weight or in the seminiferous tubules on exposure to manganese sulphate at concentrations up to 15 000 ppm.

 

Tallate

According to Regulation (EC) No 1907/2006 Annex V substances obtained from natural sources and not modified such as vegetable fats and oils as well as fatty acids from C6 to C24 and their potassium, sodium, calcium and magnesium salts are excluded from the obligation to register.

The substance subjected to registration is a mixture of different saturated and unsaturated C16 -C18 fatty acids. Based on this, the following endpoint is covered by publicly available data on fatty acids with the same or similar structure.

The long history of safe use of these acids and their related glycerides and food oils, as well as the GRAS status for several of the fatty acids and their salts, indicate the low potential for reproductive toxicity of these chemicals.

According to the HERA document on fatty acid salts a “three-generation reproductive study on a C10 fatty did not produce any reproductive effects. Hendrich et al. (1993) conducted a study in which three generations of CBA/2 and C57Bl/6 mice were reared on semipurified diets containing 8.6% crude Cuphea oil. The Cuphea oil contained 76% capric acid (C10 fatty acid). Males of each generation were housed individually and fed for 13-weeks. Food intakes and body weights were measured weekly. The diet containing Cuphea oil did not impair reproductive parameters or cause any pathology in the mouse tissues examined. Cuphea oil moderately suppressed body weights and food intakes of mice in some groups between 4 and 13-weeks of age, but had no long-term effects on body weight, food intake or cholesterol status” (HERA, 2002).

 

“In a 90 day study, groups of ten rats/sex/group were administered 9-Octadecenoic acid in the diet at 0, 3300, 6100, 14,000 mg/kg bw/day. There were no effects on gonads weights, and no gross or histopathological findings for testes, seminal vesicle, ovary, uterus, or prostate. The NOAEL for reproductive effects was 14,000 mg/kg bw, the highest dose tested” (OECD SIDS, 2014).

 

“Also, it is worth bearing in mind when considering the reproductive toxicity of fatty acids and their salts, that due to their innocuous nature, fats and oils are commonly used as controls and as vehicles in animal toxicity studies. For example, OECD Guideline 408 (repeated dose 90-day oral toxicity study in rodents) recommends the use of “a solution/emulsion in oil (e.g. corn oil)” as a vehicle where an aqueous vehicle is not suitable (OECD, 1993)” (HERA, 2002).

 

This along with the long history of safe use of the fatty acids indicate the low potential for reproductive toxicity of these chemicals.

 

Fatty acids, tall-oil, manganese salts

Information on the individual moieties manganese and fatty acids, tall-oil will be used for the hazard assessment and, when applicable, for the risk characterisation of fatty acids, tall-oil, manganese salts. For the purpose of hazard assessment of fatty acids, tall-oil, manganese salts, the point of departure for the most sensitive endpoint of each moiety will be used for the DNEL derivation. Since naturally occurring fatty acids are void of any human health hazard potential, the hazard assessment will be derived based on the toxicological information for manganese. In case of manganese in fatty acids, tall-oil, manganese salts, the NOAEL of 72.8 mg Mn/kg bw/day obtained in a repeated dose toxicity study will be used.

Effects on developmental toxicity

Description of key information

No toxicity data on adverse effects on development of the offspring with fatty acids, tall-oil, manganese salts are available, thus the reproductive toxicity will be addressed with existing data on the individual moieties manganese and tallate. 

Fatty acids, tall-oil, manganese salts is not expected to impair development, since the moiety manganese has not shown adverse effects on developmental. The moiety fatty acids, tall-oil is obtained from natural sources and excluded from the obligation to register.

Effect on developmental toxicity: via oral route

Endpoint conclusion:

no adverse effect observed

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

Read-across approach

Selected endpoints for the human health hazard assessment are addressed by read-across, using a combination of data on the metal cation and the organic acid anion. This way forward is acceptable, since metal carboxylates are shown to dissociate to the organic anion and the metal cation upon dissolution in aqueous media. No indications of complexation or masking of the metal ion through the organic acid were apparent during the water solubility and dissociation tests (please refer to the water solubility and dissociation in sections 4.8 and 4.21 of IUCLID). Once the individual transformation products of the metal carboxylate become bioavailable (i.e. in the acidic environment in the gastric passage or after phagocytosis by pulmonary macrophages), the “overall” toxicity of the dissociated metal carboxylate can be described by a combination of the toxicity of these transformation products, i.e. the metal cation and carboxylate anion according to an additivity approach.

Fatty acids, tall-oil, manganese salts is the manganese metal salt of fatty acids, tall-oil, which readily dissociates to the corresponding divalent manganese cation and tallate anions. The manganese cation and the tallate anions are considered to represent the overall toxicity of Fatty acids, tall-oil, manganese salts in a manner proportionate to the free acid and the metal (represented by one of its readily soluble salts). 

A detailed justification for the read-across approach is added as a separate document in section 13 of IUCLID.

Toxicity for reproduction – developmental toxicity

No toxicity data on adverse effects on development of the offspring with Fatty acids, tall-oil, manganese salts are available, thus the reproductive toxicity will be addressed with existing data on the dissociation products as detailed in the table below. Further details on the genetic toxicity of the individual constituents are given below.

 

Table: Summary of toxicity data on adverse effects on development of the offspring of Fatty acids, tall-oil, manganese salts and the individual constituents.

	Manganese sulfate (CAS# 7785-87-7)	Fatty acids, tall-oil	Fatty acids, tall-oil, manganese salts (CAS# 8030-70-4)
Pre-natal developmental toxicity study	NOAEL(rat; mat.)> 1004 mg MnSO4/kg bw/day   NOAEL(rat; dev)> 1004 mg MnSO4/kg bw/day	NOAEL > 10,000 mg/kg	No data   Not classified
Two-generation reproductive toxicity study	No data   not classified	No data   not classified	No data   not classified

 

 

Manganese

In a prenatal developmental toxicity study manganese sulphate was administered to female rats in the diet at concentration of 24, 54, 154, 504, or 1004 mg manganese /kg dry diet for 8 weeks. After 8 weeks the animals were allowed to mate. On gestational day 21 the animals were sacrificed, the uterus removed and the number of foetuses, implantation sites and resorptions were determined. The foetuses were subject to skeletal staining and the concentrations of manganese, Fe, Cu and Zn were determined in both whole foetus and maternal liver. There was no impact on foetuses at any of the doses studied. There was also no impact on reproductive parameters at any dose level. It was also observed that increasing dietary concentrations of manganese caused a decrease in iron concentration in the foetus and in the maternal liver. The effect of manganese in diet on concentration of Cu and Zn in foetus and maternal liver was relatively modest.

 

In a study by Webster and Valois (1987) pregnant female mice were treated with a single intraperitoneal injection of 12.5, 25 or 50 mg manganese sulphate on day 8, 9 or 10 of pregnancy. On day 8, the highest dose was embryolethal and the other doses induced a low incidence of neural tube defects in the surviving foetuses. The 25 mg dose caused maternal toxicity, coinciding with peak blood concentrations of 1000 ng/mL for 30 minutes. Blood levels exceeded 100 ng/mL for 24 hours. When manganese was incubated with rat embryos for 48 hours, 25 and 50 ng/mL had no effect while there was no survival at 200 ng/mL. They also looked at postnatal brain manganese after a single dose of 54Mn and found that manganese entered the foetal and neonatal brain more easily than the adult brain.

 

Tallate

According to Regulation (EC) No 1907/2006 Annex V substances obtained from natural sources and not modified such as vegetable fats and oils as well as fatty acids from C6 to C24 and their potassium, sodium, calcium and magnesium salts are excluded from the obligation to register.

The substance subjected to registration is a mixture of different saturated and unsaturated C16 -C18 fatty acids. Based on this, the following endpoint is covered by publicly available data on fatty acids with the same or similar structure. 

Available data do not provide evidence of significant developmental toxicity of fatty acid salts. The long history of safe use of the fatty acids and their related glycerides and food oils, as well as the GRAS status for several members of the fatty acids and their salts, indicate the low potential for developmental toxicity of these chemicals.

“In a study following the Chernoff/Kavlock Developmental Toxicity Screen, groups of female mice (26-30/dose) were treated via oral gavage on gestation days 8-12 with 10,000 mg/kg bw/day of 9,12-octadecadienoic acid. There were no effects on number of litters, number of resorptions, number of pups/litter, number of live and dead births, postnatal survival rates, pup weights at days 1 and 3 or external abnormalities among dead pups. The NOEL for developmental toxicity is >= 10,000 mg/kg bw/day for mice with exposure on gestation days 8-12” (OECD SIDS, 2014).

 

“Ishii et al. (1990) studied the effects of natural soap on the development of mouse embryos cultured in vitro. They found that there was no effect on embryo development at concentrations up to 0.05%. More than 0.05% natural soap gave rise to precipitates in the culture medium” (HERA, 2002).

 

“In a two generation study (similar to OECD TG 416; the initial treatment period was decreased to three weeks versus ten weeks), groups of rats (30 females/15 males/dose) were administered 0, 5 or 10% of fatty acids, tall-oil, CAS No 61790-12-3 in the diet, (equivalent to approximately 0, 2500 or 5000 mg/kg bw/day). The parental (F0) generation began treatment at 80 days of age and were mated at 100 days of age. Treatment continued through the weaning of the first generation (F1). After weaning, 20 F1 males and 20 F1 females per group were maintained on the parental diet. At 100 days of age, these rats were mated and allowed to deliver pups (F2). Treatment did not affect the number of live born or stillborn F1 litters and pups, or F1 weaning weight. No treatment-related changes in fertility, viability, lactation, or gestation indices were measured. Hematology, clinical chemistry and urinalysis parameters were unchanged, and gross and microscopic pathology revealed no treatment-related effects. The NOAEL for developmental toxicity is >= ca. 5000 mg/kg bw/day for rats exposed for two generations” (OECD SIDS; 2014).

 

It is also important to bear in mind when considering the toxicity of fatty acids and their salts that due to their innocuous nature, fats and oils are commonly used as controls and as vehicles in animal toxicity studies. For example OECD Guideline 408 recommends the use of “a solution/emulsion in oil (e.g. corn oil)” where an aqueous vehicle is not suitable (OECD, 1993).

Beside of animal data also human breastfeeding indicate that fatty acids are essential for human development. A breast-fed of 3 months age has an average weight of 6.5 kg (WHO 2013) and the infant ingests approx. 180mL/kg bw of milk per day (Riordan 2001), being 1170 mL for a baby at an age of 3 months. The fat content of mother milk is approx. 4.2% (United Nations 1996), with a content of stearic acid of approx. 7.5% (total content of C18 fatty acids: C18:0, C18:1, C18:2 and C18:3 = 58.2%) (Finley et al. 1985). This results in a total “exposure” for a 3 month old baby of 3.7 g stearic acid per day, being 570 mg/kg bw/day.

 

 

Fatty acids, tall-oil, manganese salts

Information on the individual moieties manganese and fatty acids, tall-oil will be used for the hazard assessment and, when applicable, for the risk characterisation of fatty acids, tall-oil, manganese salts. For further information on the toxicity of the individual moieties, please refer to the relevant sections in the IUCLID and CSR. For the purpose of hazard assessment of fatty acids, tall-oil, manganese salts, the point of departure for the most sensitive endpoint of each moiety will be used for the DNEL derivation. Since naturally occurring fatty acids are void of any human health hazard potential, the hazard assessment will be derived based on the toxicological information for manganese. In case of manganese in fatty acids, tall-oil, manganese salts, the NOAEL of 72.8 mg Mn/kg bw/day obtained in a repeated dose toxicity study will be used.

Justification for classification or non-classification

Fatty acids, tall-oil, manganese salts is not expected to impair fertility or development, since the two moieties manganese and tallate have not shown adverse effects in reproduction or prenatal developmental toxicity studies. Additionally, the moiety fatty acids, tall-oil is obtained from natural sources and excluded from the obligation to register. No classification for toxicity to reproduction is indicated according to the classification, labelling and packaging (CLP) regulation (EC) No 1272/2008.