Magnesium di(acetate)

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation

Remarks:

in vivo

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The analogue Citric Acid which shares the same functional group with Magnesium Acetate, also has comparable values for the relevant molecular properties for the skin sensitisation endpoint.

Cross-reference

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

other: read-across

Title:

Unnamed

Year:

2010

Materials and methods

Principles of method if other than guideline:

Read-across approach from published experimental data from a skin prick testing on the analogue Citric acid.

GLP compliance:

not specified

Type of study:

other: read-across from a skin prick testing with an analogue

Test material

Test material information

Constituent 1

Reference substance name:

Citric acid

EC Number:

201-069-1

EC Name:

Citric acid

Cas Number:

77-92-9

IUPAC Name:

citric acid

Details on test material:

- Name of test material (as cited in study report): Citric acid
- Molecular formula (if other than submission substance): C6H8O7
- Molecular weight (if other than submission substance): 192.1
- Smiles notation (if other than submission substance): OC(=O)CC(O)(CC(O)=O)C(=O)O
- InChl (if other than submission substance): InChI=1/C6H8O7/c7-3(8)1-6(13,5(11)12)2-4(9)10/h13H,1-2H2,(H,7,8)(H,9,10)(H,11,12)
- Structural formula attached as image file (if other than submission substance): see Fig. in attached report

Results and discussion

In vivo (non-LLNA)

Results

Results 1

Reading:

1st reading

Hours after challenge:

0.25

Group:

test chemical

Dose level:

2.5 %

No. with + reactions:

3

Total no. in group:

91

Clinical observations:

Weals

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 0.25. Group: test group. Dose level: 2.5 %. No with. + reactions: 3.0. Total no. in groups: 91.0. Clinical observations: Weals.

Results 2

Reading:

rechallenge

Hours after challenge:

0.25

Group:

test chemical

Dose level:

2.5 %

No. with + reactions:

0

Total no. in group:

11

Clinical observations:

No effects

Remarks on result:

other: Reading: rechallenge. . Hours after challenge: 0.25. Group: test group. Dose level: 2.5 %. No with. + reactions: 0.0. Total no. in groups: 11.0. Clinical observations: No effects.

Results 3

Reading:

1st reading

Hours after challenge:

0.25

Group:

negative control

Dose level:

0

No. with + reactions:

0

Total no. in group:

247

Clinical observations:

No effects

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 0.25. Group: negative control. Dose level: 0. No with. + reactions: 0.0. Total no. in groups: 247.0. Clinical observations: No effects.

Any other information on results incl. tables

Based on the experimental results obtained with the analogue Citric acid (Citric acid, 2.5 % aqueous solution, is not sensitizing for the human skin), the read-across approach was applied and the substance Magnesium acetate is considered to be also not sensitizing for the human skin. 

The analogue Citric acid which shares the same functional group with Magnesium acetate, also has comparable values for the relevant molecular properties. These properties are:

- a low log Pow value, which is -1.72 for Citric acid, and -1.38 for Magnesium acetate,

- a high water solubility, which is 1330 g/L for Citric acid, and 16600 mg/L at 25 ºC for Magnesium acetate, and

- similar molecular weights, which are 192.1 for Citric acid, and 142.40 for Magnesium acetate.

Both chemicals are grouped together by US EPA category group Carboxylic Food Acids and Salts Category.

As indicated in the European Chemical Agency Practical Guide 6 “How to report read –across and categories”, the structural grouping was realized using “OECD QSAR APPLICATION TOOL BOX” version 1.1.0.Presented results show that both substances have common (eco)toxicological behavior (attachment).

Table 1. Data Matrix, Analogue Approach.

CAS Number			Source chemical 77-92-9	Target chemical 142-72-3
CHEMICAL NAME			Citric acid	Magnesium acetate
PHYSICO-CHEMICAL DATA
Melting Point			Measured data: 153 ºC	Measured: 327.4 ºC
Boiling Point			Decomposes	No data
Density			Measured data: 1.665 g/cm3 at 20 ºC	Experimental results: Relative density: 1.42
Vapour Pressure			Estimated data: 5.6E-09 mm Hg	Calculated data: 0.0000179 mm Hg at 25 ºC
Partition Coefficient (log Kow)			Measured data: -1.72	Calculated data: -1.38
Water solubility			Measured data: 1330 g/L	Experimental results: 166 g/L at 25 ºC
ENVIRONMENTAL FATE and PATHWAY
Aerobic Biodegradation			Experimental results: Readily biodegradable	Read-across from Sodium Acetate (category analogue): Readily biodegradable
ENVIRONMENTAL TOXICITY
Acute Toxicity to Fish			Experimental data: (96 h) LC 50 = 1516 mg/L	Weight of evidence:   Read-across from Sodium acetate (category analogue) based on molecular weights:   (96 h) LC 50 > 86.79 mg/L(Brachydanio rerio)     Read-across from Potassium acetate (category analogue) based on molecular weights:   (96 h) LC 50 > 362.75 mg/L (Oncorhynchus mykiss)   (96 h) LC 50 > 362.75 mg/L (Cyprinodon variegatus)   (96 h) LC 50 > 360.1 mg/L(Brachydanio rerio)
Acute Toxicity to Aquatic Invertebrates			Experimental data: (48 h) EC 50 = 1535 mg/L	Weight of evidence:   Read-across from Potassium acetate (category analogue) based on molecular weights:   (48 h) EC 50 > 333.36 mg/L(Daphnia magna) (48 h) EC 0 = 204.59 mg/L (Daphnia magna)   Read-across from Sodium acetate (category analogue) based on molecular weights:   (48 h) EC 50 > 867.98 mg/L(Daphnia magna)
Toxicity to Aquatic Plants			Experimental data: (72 h) EC 50 = 640 mg/L	Key studies: Read-across from Potassium acetate (category analogue) based on molecular weights:   (72 h) EC 50 > 362.75 mg/L (Skeletonema costatum) (72 h) NOEC = 362.75 mg/L (Skeletonema costatum)     Supporting studies: Read-across from the analogue substance Acetic Acid, based on molecular weights:   (8 d) Toxicity threshold (TT) = 4746.67 mg/L (Scenedesmus quadricauda)
MAMMALIAN TOXICITY
Acute Toxicity: Oral			Experimental data: LD 50 = 5790 – 7100 mg/kg bw (mice) LD 50 = 11700 mg/kg bw (rats)	Key study: Read-across from Calcium Acetate (category analogue), based on molecular weights:  LD50 = 2422 mg/kg bw
Acute Toxicity: Inhalation			No data	Key study:   Read-across from Calcium Acetate (category analogue), based on molecular weights: (4 h) LC50 > 5.04 mg/L (rats)
Acute Toxicity: Dermal			Experimental data:   A 4-hour skin irritation study in rabbits exposed to a solution containing 60% citric acid caused erythema and edema. This study did not assess a lethal dose value. TheLD50 was not provided.	Key study:   Read-across from the analogue Fumaric acid, based on molecular weights: LD50 (4 h) > 24530.58 mg/kg bw (female New Zealand White rabbits)
Skin Sensitization			Experimental results:   Citric acid (2.5 % aqueous solution) is not sensitizing for the human skin.   No allergic reactions were seen when 60 patients with hand eczema, all of whom were involved in handling food, were patch tested (covered contact, probably 24 hr) with 2.5% citric acid in petrolatum.	Weight of evidence:   Read-across from the analogue substances Citric acid, Glycolic acid, Sodium Glycolate, Lactic acid, Ammonium lactate, and Triacetin, based on functional group:   All these substances were not sensitising for human and guinea pigs. Based on these results, Magnesium acetate is also considered to be not sensitising.
Repeated Dose Toxicity			Repeated dose toxicity: oral: Experimental results:   In a 150-day study with male New Zealand White rabbits daily treated by feed, theNOAEL was 1500 mg/kg bw/day(based on no effects observed at the only dose tested).   In a 6-week study with male Sprague-Dawley rats daily treated by feed, theNOAEL was 4800 mg/kg bw/day(based on no effects observed at the highest dose tested).	Repeated dose toxicity: oral: Weight of evidence:   Read-across from Sodium acetate (category analogue), based on molecular weights:   Repeated dose toxicity: oral: 112-day study in male Wistar rats. The NOAEL was determined as 0.0087 mg/kg bw/day.   Repeated dose toxicity: oral: 3-month study in male Long-Evans rats. The NOAEL was determined as 18.23 mg/kg bw/day.   Repeated dose toxicity: oral: 4-week study in male Wistar rats. The NOAEL was determined as 3124.71 mg/kg bw/day.   Repeated dose toxicity: oral: 8-month study in male Long-Evans rats. The NOAEL was determined as 0.043 mg/kg bw/day.     Read-across from the analogue Citric acid, sodium salt, based on molecular weights:   TheNOAEL >= 49.88 mg/kg bw/day, in rats daily treated by feed for ca. 1 year.
Genetic Toxicity in vitro		-         Gene mutation in bacteria	Experimental data:   In a bacterial reverse mutation assays usingS. typhimurium(TA97, TA98, TA100 and TA104) in the presence and absence of metabolic activation and up to 2000μg/plate, citric acid was not mutagenic.	Experimental data: Weight of evidence:   Read-across from Sodium Acetate (category analogue) based on functional group:   Reverse mutation assay using S. typhimurium strains TA92, TA1535, TA100, TA1537, TA94 and TA98 with metabolic activation. Resultslead to the conclusion that Magnesium Acetate did not cause point mutations in the microbial systems. Read-across from the analogue substance Acetic Acid, based on functional group: MagnesiumAcetate is considered to be not mutagenic on S. typhimurium TA 98, TA 100, TA 1535, TA 97, and/or TA 1537, with and without metabolic activation.
		Chromosomal aberration	No data	Weight of evidence: Read-across from Sodium Acetate (category analogue) based on functional group:   In an in vitro chromosomal aberration assay with a Chinese hamster fibroblast cell line, CHL, without metabolic activation systems, Magnesium acetate did not induce chromosomal aberrations(including gaps). Read-across from the analogue substance Acetic Acid, based on functional group: MagnesiumAcetate is considered as not clastogenic on Chinese hamster Ovary (CHO) cells, without metabolic activation.
		Mammalian gene mutation	No data	Weight of evidence: Read-across from the analogue Acetic anhydride, based on functional group: Magnesium acetate is considered to be not mutagenic on mouse lymphoma L5178Y cells, with and without metabolic activation. Read-across from the analogue Phenoxyacetic acid, based on functional group: Magnesium acetate is considered to be not mutagenic on Chinese hamster ovary cells, with and without metabolic activation.
Genetic Toxicity in vivo			Experimental data:   In a Dominant Lethal assay using male/female rats dosed at 3 g/kg for 5 days, citric acid did not induced germ cell genotoxicity.	Read-across from experimental results obtained with Sodium Acetate:   The Testicular DNA-synthesis inhibition test (DSI test) on male mice provides evidence that Magnesium acetate is not genotoxic in animals (basis of the method: measuring 3H-thymidine incorporation).
Carcinogenicity			No data	No data
Reproductive Toxicity			TOXICITY TO REPRODUCTION: Experimental data: In a one-generation oral reproductive toxicity study, female rats and mice were daily treated with citric acid before, during, and after mating. The NOAEL was equal or greater than 2500 mg/kg bw/day (basis for effect: number of pregnancies, number of young born, or survival of young). In a fertility study, female rats were exposed to citric acid in their daily diet for several months. TheNOAEL (reproductive toxicity) was 600 mg/kg bw/day(based on no effects observed at the only dose tested).     DEVELOPMENTAL TOXICITY / TERATOGENICITY:   Experimental data:   In a one-generation oral reproductive toxicity study, female rats and mice were daily treated with citric acid before, during, and after mating. The NOAEL was equal or greater than 2500 mg/kg bw/day (basis for effect: number of pregnancies, number of young born, or survival of young).	TOXICITY TO REPRODUCTION: Weight of evidence: Read-across from the analogue Citric Acid, based on molecular weights: A study on rats and mice daily treated by feed before, during, and after mating. For Magnesium Acetate, the NOAEL is calculated to be equal or greater than 2779.80 mg/kg bw/day (basis for effect: number of pregnancies, number of young born, or survival of young). A fertility test on female rats daily treated by feed for several months. For Magnesium Acetate, the NOAEL is calculated to be 667.15 mg/kg bw/day, and LOAEL greater than 667.15 mg/kg bw/day for reproductive effects. Read-across from the analogue Citric Acid, sodium salt, based on molecular weights: A fertility study on female rats daily treated by feed for several months. For Magnesium Acetate, the NOAEL is calculated to be 49.88 mg/kg bw/day, and LOAEL greater than 49.88 mg/kg bw/day for reproductive effects.   DEVELOPMENTAL TOXICITY / TERATOGENICITY: Weight of evidence: Read-across from Sodium Acetate (category analogue) based on molecular weights:   Pregnant CD-1 mice were treated by oral gavage with Sodium Acetate on days 8-12 of gestation. For Magnesium Acetate, theNOAEL is calculated to be equal or greater than 867.98 mg/kg bw/day for maternal toxicity and neonatal effects (mortality and body weight).   Read-across from the analogue Citric Acid, based on molecular weights: A study on rats and mice daily treated by feed before, during, and after mating. For Magnesium Acetate, the NOAEL is calculated to be equal or greater than 2779.80 mg/kg bw/day (basis for effect: number of pregnancies, number of young born, or survival of young). Read-across from the source chemical Calcium Formate to the target chemical, based on molecular weights: A three-generation drinking water study was performed. For Magnesium Acetate, the NOAEL is calculated to be equal or higher than 218.89 mg/kg bw/day. Read-across from theanalogue substanceAcetic Acid, based on molecular weights: A one-generation study was performed on female mice, rats and rabbits with Acetic Acid. The read-across approach was applied and the NOAEL with the substance Magnesium acetate is calculated to be equal or greater than 1898.67 mg/kg bw/day for maternal and developmental toxicity in mice, rats, and rabbits.

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information

Conclusions:

Magnesium acetate is considered to be not sensitizing for the human skin.

Executive summary:

Based on the experimental results (reported under the endpoint record 07.04.01_01 Citric acid) obtained with the analogue Citric acid (Citric acid, 2.5 % aqueous solution, is not sensitizing for the human skin), the read-across approach was applied and the substance Magnesium acetate is considered to be also not sensitizing for the human skin.