Sulfates of potassium, sodium and calcium, byproduct from fermentation

Endpoint summary

Description of key information

Acute oral toxicity:

Read-across from three source analogues Potassium sulfate (CAS 7778-80-5), Sodium sulfate (CAS 7757-82-6) and Calcium sulfate (CAS 7778-18-9): The three substances are not considered to be hazardous for acute oral toxicity in the rat (Product Safety Laboratories, 2000; Harlan Laboratories LTD, 2010; NIER, 2003). Based on the analogy approach applied, the target substance is not considered to be hazardous for acute oral toxicity according to CLP (LD50 > 2000 mg/kg bw is attributed).

Acute dermal toxicity:

Dermal LD50 (rat) > 2000 mg/kg bw with no mortality and no systemic clinical signs (Reliability 1 key study; GLP compliant; OECD 402 test guideline) (CiToxLAB Hungary Ltd., 2017)

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Reference 1

Endpoint:

acute toxicity: oral

Type of information:

other: 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: read-across data

Remarks:

original study is of reliability 2 (a limited documented study according to test guidelines and GLP).

Qualifier:

according to guideline

Guideline:

OECD Guideline 425 (Acute Oral Toxicity: Up-and-Down Procedure)

GLP compliance:

yes

Test type:

up-and-down procedure

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

According to test guidelines, no further information

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

Prior to use, the test substance was ground in a coffee mill and administered by gavage as a 60% w/w suspension in distilled water (preliminary solubility testing indicated that suspensions in excess of 60% were too viscous to be administered properly).

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

3

Control animals:

not specified

Details on study design:

An initial dose of two thousand milligrams of the test substance per kilogram of bodyweight was administered to one healthy female rat by oral gavage. Due to the absence of mortality in this animal a second female received the same dose level. Following the completion of dosing and 100% survival in a total of three females, a group of three males was tested (simultaneously) at the above dose level. All animals were observed for mortality, signs of gross toxicity, and behavioral changes at least once daily for 14 days after dosing. Bodyweights were recorded prior to administration and again on Days 7 and 14 (termination) after dosing. Necropsies were performed on all animals at terminal sacrifice.

Statistics:

no data

Preliminary study:

not relevant

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Mortality:

All animals survived.

Clinical signs:

other: All animals appeared active and healthy throughout the study period.

Gross pathology:

No signs of toxicity were observed.

Other findings:

no

Interpretation of results:

GHS criteria not met

Conclusions:

Potassium magnesium sulphate is considered not harmful for acute oral toxicity.

Reference 2

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: Peer reviewed secondary data source.

Guideline:

other: not mentioned

GLP compliance:

not specified

Test type:

other: acute oral toxicity

Species:

rat

Strain:

not specified

Sex:

not specified

Details on test animals or test system and environmental conditions:

no data

Route of administration:

oral: unspecified

Vehicle:

not specified

Details on oral exposure:

no data

Details on study design:

no data

Key result

Sex:

not specified

Dose descriptor:

LD50

Effect level:

6 600 mg/kg bw

Interpretation of results:

other: not specified

Conclusions:

LD50 (rat) for Potassium sulfate = 6600 mg/kg bw

Reference 3

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

18-Feb-2010 to 11-Mar-2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

This study has been performed in compliance with the Swiss Ordinance relating to Good Laboratory Practice, adopted May 18th, 2005 [SR 813.112.1]. This Ordinance is based on the OECD Principles of Good Laboratory Practice, as revised in 1997 and adopted November 26th, 1997 by decision of the OECD Council [C(97)186/Final].

Qualifier:

according to guideline

Guideline:

OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.1 tris (Acute Oral Toxicity - Acute Toxic Class Method)

Deviations:

no

GLP compliance:

yes

Test type:

acute toxic class method

Limit test:

yes

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan Laboratories B.V., Kreuzelweg 53, 5961 NM Horst / The Netherlands
- Age when treated: 10 weeks
- Body Weight when treated: 170.3 g – 187.4 g
Housing: In groups of three in Makrolon type-4 cages with wire mesh tops and standard softwood bedding (‘Lignocel’ J. Rettenmaier&Söhne GmbH&CoKG, 73494 Rosenberg / Germany, imported by Provimi Kliba AG, 4303 Kaiseraugst / Switzerland).
- Diet: Pelleted standard Provimi Kliba 3433 rat/mouse maintenance diet, batch no. 60/09 (Provimi Kliba AG, 4303 Kaiseraugst / Switzerland) ad libitum (except for the overnight fasting period prior to intubation and approximately 3-4 hours post dose).
Water: Community tap water from Füllinsdorf ad libitum.
-Acclimatization period: 18-Feb-2010 to 22-Feb-2010 (the first three females), 18-Feb-2010 to 24-Feb-2010 (the remaining three females)

ENVIRONMENTAL CONDITIONS
- Temperature: 22 ± 3 °C
- Humidity: between 30 - 70%
- Air changes: 10 - 15 air changes per hour
- Photperiod: 12 hours light and 12 hours dark

IN-LIFE DATES: 23-Feb-2010 to 11-Mar-2010

Route of administration:

oral: gavage

Vehicle:

polyethylene glycol

Remarks:

(PEG 300)

Details on oral exposure:

The animals received a single dose of the test item by oral gavage administration at 2000 mg/kg body weight after being fasted for approximately 17 to 20 hours (access to water was permitted). Food was provided again approximately 3 hours after dosing.

TEST MATERIAL
Dose levels were in terms of the test item as supplied by the Sponsor.
The dose formulations were prepared shortly before each dosing occasion using a magnetic stirrer, a spatula and an Ultra-Turrax as homogenizers.

The dosing volume was 10 mL/kg body weight.

Doses:

2000 mg/kg at a dose volume of 10 mL/kg

No. of animals per sex per dose:

3 females

Control animals:

no

Details on study design:

Threee females were first treated.Since no relevant clinical signs were observed and no death occurred 48 hours after test item administration, the test was completed using the three remaining females.
- Duration of observation period following adminsitration: 15 days
- Frequency of observation period following administration: within the first 30 minutes and at approximately 1, 2, 3 and 5 hours after administration on test day 1. Once daily during days 2-15.
- Necropsy of survivors performed: yes
- Other examinations performed: viability/ Mortality, clinical signs, body weights

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Mortality:

All animals survived until the end of the study period with the exception of one animal, which spontaneously died shortly after administration due to application in wrong way.

Clinical signs:

other: Slight sedation was observed in two animals from 1 to 2 hours after administration and persisted as moderate in one animal up to the 5-hour reading. Hunched posture was also noted in the two animals at the 2-hour reading and persisted in one animal up to

Gross pathology:

Dark red lungs congested, in which contained dark red hemorrhagic-watery fluid, were noted at necropsy in the animal which died spontaneously due to a technical failure.

The remaining animals were devoid of any macroscopic findings at the scheduled necropsy.

Interpretation of results:

GHS criteria not met

Conclusions:

The median lethal dose of Sodium Sulphate after single oral administration to female rats, observed over a period of 14 days, is:
LD50 (female rat): greater than 2000 mg/kg body weight

Executive summary:

Two groups, each consisting of three female RccHan:WIST (SPF) rats, were treated with Sodium Sulphate by single oral gavage administration at a dosage of 2000 mg/kg body weight. The test item was formulated in PEG300 at a concentration of 0.2 g/mL and administered at a dosing volume of 10 mL/kg.

 

The animals were examined daily during the acclimatization period and mortality, viability and clinical signs were recorded. All animals were examined for clinical signs within the first 30 minutes and approximately 1, 2, 3 and 5 hours after treatment on day 1 and once daily during test days 2-15. Mortality/viability was recorded within the first 30 minutes and approximately 1, 2, 3 and 5 hours after administration on test day 1 (with the clinical signs) and twice daily during days 2-15. Body weights were recorded on day 1 (prior to administration) and on days 8 and 15.All animals were necropsied and examined macroscopically.

 

All animals survived until the end of the study period with the exception of one animal, which spontaneously died shortly after administration due to a technical failure.

 

Clinical signs, including sedation, hunched posture and ruffled fur, were noted in two animals on test day 1 and were distributed from the 1- to the 5-hour post-dose. Both animals were devoid of any clinical signs from test day 2 to the end of the study. No clinical signs were observed in the surviving females throughout the observation period.

 

The body weight of the animals was within the range commonly recorded for this strain and age.

 

Dark red congested lungs, with dark red hemorrhagic-watery fluid, were noted at necropsy of the animal which died spontaneously immediately after gavage. These findings clearly suggested technical failure during the gavage procedure.

The median lethal dose of Sodium Sulphate after single oral administration to female rats, observed over a period of 14 days, is:

LD50 (female rat): greater than 2000 mg/kg body weight

Reference 4

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 420 (Acute Oral Toxicity - Fixed Dose Method)

GLP compliance:

yes

Test type:

fixed dose procedure

Species:

rat

Strain:

Sprague-Dawley

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: 9 ~ 11 weeks
- Weight at study initiation: 194.9 ~ 206.6 g (sighting study), 194.9 ~ 203.6 g (main study)
- Fasting period before study: Animals were fasted the night before administration but fodder was offered 3 to 4 hours after the administration

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

DOSAGE PREPARATION: Test substance was dissolved in the distilled water on the day of administration

- Rationale for the selection of the starting dose: In order to determine the appropriate starting dose for the main test, 50, 300 and 2,000 mg/kg of test substance were administered to each animal in a sighting study, but there were no toxic effects at least 2 days after the administration.

Doses:

50, 300 and 2000 mg/kg b.w

No. of animals per sex per dose:

In the screening study one female rat was used in each of the three doses. In the main test a further 4 female rats were administered with 2000 mg/kg of the test material.

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Mortality, clinical signs and toxic effects were observed 0.5, 1, 2, 3 and 4 hours after the treatment on the day of administration, after that were observed at least once a day till necropsy. Body weight was measured on day 1, 7 and 14.
- Necropsy of survivors performed: yes

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

> 1 581 mg/kg bw

Remarks on result:

other: The LD50 for calcium sulfate dihydrate was > 2000 mg/kg bw. The value has been calculated for calcium sulfate anhydrous

Mortality:

No mortality was observed within every dose level

Clinical signs:

other: There were no specific clinical signs during test period

Gross pathology:

No abnormal necropsy opinions in relation to administration of calcium sulfate, dihydrate.

Table 1: Mortality of Females (Group Summary)

 

Dose (mg/kg)	No. Dead/No. Dosed	Number of Deaths
		Days After Dosing
		1	2	3	4	5	6	7	8	9	10	11	12	13	14
50	0/1	0	0	0	0	0	0	0	0	0	0	0	0	0	0
300	0/1	0	0	0	0	0	0	0	0	0	0	0	0	0	0
2000	0/5	0	0	0	0	0	0	0	0	0	0	0	0	0	0

 

Table 2: Incidence of Clinical Signs in Females (Group Summary)

 

Signs observed	Dose level mg/kg	50	300	2000
Appears normals		1/1*	1/1	5/5
*: No. of animals with the sign/No. of animals examined

 

Table 3: Body Weights of Females (group summary)

 

Dose (mg/kg)	Animal Number
		Day 0	Day 1	Day 7	Day 14	Gain
50	1	194.9	214.0	234.2	243.0	48.1
300	2	200.2	225.6	229.6	235.2	35.0
2000	3	206.6	224.6	235.2	247.6	41.0
	4	194.9	214.6	222.4	227.8	32.9
	5	201.8	220.8	232.0	236.2	34.4
	6	203.6	217.6	220.0	224.8	21.2
	7	198.4	217.8	219.4	234.2	35.8
	Mean	201.1	219.1	225.8	234.1	33.1
	SD	4.55	3.79	7.30	8.84	7.30
	N	5	5	5	5	5

 

Table 4: Gross Findings of Females (Group Summary)

 

Dose (mg/kg)	Gross Observation		Frequency
	Location	Observation	Mortalities	Survivors
0	No gross findings		0/0*	1/1
300	No gross findings		0/0	1/1
2000	No gross findings		0/0	5/5
* No. of animals with the sign/No. of animals examined

Interpretation of results:

GHS criteria not met

Remarks:

The hydrated form exhibited no signs of toxicity whatsoever at the highest, dose therefore even with a correction to the anhydrous form which is lower that the limit dose, the anhydrous form is also considered not classified.

Conclusions:

The study was performed with calcium sulfate dihydrate which gave an LD 50 >2000 mg/kg. Based on this result the oral LD50 of calcium sulfate anydrous is >1581 mg/kg b.w

Reference 5

Endpoint:

acute toxicity: oral

Type of 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: read across from reliability 1 or 2 studies

Justification for type of information:

See attached document.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Species:

rat

Key result

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Interpretation of results:

GHS criteria not met

Conclusions:

Based on read-across data from three source analogues Potassium sulfate (CAS 7778-80-5), Sodium sulfate (CAS 7757-82-6) and Calcium sulfate (CAS 7778-18-9) (all three analogues are not considered to be hazardous for acute oral toxicity in the rat), the target substance is not considered to be hazardous for acute oral toxicity according to CLP (LD50 > 2000 mg/kg bw is attributed).

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Quality of whole database:

GLP compliant read across studies performed according to current guidelines

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 7 April 2017 to 2 June 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

yes

Remarks:

Relative humidity value (28%) outside the expected range of 30-70% was recorded at one time. This deviation was considered to have no impact on the outcome of the study.

GLP compliance:

yes (incl. QA statement)

Test type:

standard acute method

Limit test:

yes

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: EXP LIberica Lote Al16503047
- Expiration date of the lot/batch: 30 November 2019
- Purity test date: 1 February 2017

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Controlled room temperature (15-25 deg Celsius, below 70% relative humidity) protected from light and humidity
- Stability under test conditions: not applicable
- Solubility and stability of the test substance in the solvent/vehicle: not applicable

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
The test item was ground to a fine powder before the application. Sufficient water was used to dampen the test material to ensure good contact with the skin.

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories, Research Models and Services, Germany
- Females (if applicable) nulliparous and non-pregnant: yes
- Age at study initiation: Young adult rats
- Weight at study initiation: Between 219 g and 266 g
- Fasting period before study: No
- Housing: Type II. polypropylene/polycarbonate
- Diet (e.g. ad libitum): ssniff® SM R/M "Autoclavable complete diet for rats and mice breeding and maintenance", ad libitum
- Water (e.g. ad libitum): tap water from the municipal supply, as for human consumption from a 500 mL bottle, ad libitum
- Acclimation period: 5 Days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20.4–24.7°C
- Humidity (%): 28–61%
- Air changes (per hr): 15-20 air exchanges/hour
- Photoperiod (hrs dark / hrs light): 12 hours daily, from 6.00 a.m. to 6.00 p.m.

IN-LIFE DATES: From: 6 April 2017 To: 25 April 2017

Type of coverage:

semiocclusive

Vehicle:

water

Details on dermal exposure:

TEST SITE
- Area of exposure: back of the animals
- % coverage: approximately 10% area of the total body surface
- Type of wrap if used: Sterile gauze pads maintened with adhesive hypoallergenic plaster.The entire trunk was wrapped with semi occlusive plastic wrap for 24 hours

REMOVAL OF TEST SUBSTANCE
- Washing (if done): washing with water at body temperature
- Time after start of exposure: 24 hours

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 2000 mg/kg bw
- Concentration (if solution): not applicable
- Constant volume or concentration used: adjusted to animal bodyweight
- For solids, paste formed: yes

Duration of exposure:

24 hours

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

5 animals per sex per dose were used

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Clinical observations were performed on the day of treatment at 1 and 5 hours after application of the test item and once each day for 14 days thereafter. Observations included the skin and fur, eyes and mucous membranes, the respiratory, circulatory, autonomic and central nervous system, somatomotor activity and behaviour pattern. Particular attention was directed to observation of tremors, convulsions, salivation, diarrhoea, lethargy, sleep and coma. The body weights were recorded on Day 0 (before the test item administration) and on Days 7 and 14 (before necropsy). Adverse skin reactions at the site of application were recorded daily following the removal of the dressing.
- Necropsy of survivors performed: yes

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

The test item did not cause mortality at the dose level of 2000 mg/kg bw.

Clinical signs:

other: There were no systemic clinical signs noted in any animal throughout the study

Gross pathology:

There was no evidence of any gross macroscopic changes at a dose level of 2000 mg/kg bw.

Other findings:

No adverse local dermal signs were observed after treatment with the test item or during the 14 days observation period.

TABLE 1:            Clinical Observations

 

DOSE LEVEL: 2000mg/kg bw                                                                                           SEX:MALE

Cage No.

Animal No.

Observations

Observation days

Frequency

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

1h

5h

1

7970

Symptom Free

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+

16/16

2

7971

Symptom Free

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+

16/16

3

7972

Symptom Free

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+

16/16

4

7973

Symptom Free

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+

16/16

5

7974

Symptom Free

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+

16/16

 

DOSE LEVEL: 2000mg/kg bw                                                                                      SEX:FEMALE

Cage No.

Animal No.

Observations

Observation days

Frequency

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

1h

5h

6

7985

Symptom Free

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+

16/16

7

7986

Symptom Free

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+

16/16

8

7987

Symptom Free

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+

16/16

9

7988

Symptom Free

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+

16/16

10

7989

Symptom Free

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+

16/16

 

Remarks:         += present

h =hour(s)               Treatment day = Day0

Frequency of observation = number of occurence of observation / total number of observations

 

TABLE 2:            Body Weight Data

 

DOSE LEVEL: 2000mg/kgbw                                                                              SEX:MALE

Cage No.	Animal No.	Body weight (g) Days			Body Weight Gain (g)
		0	7	14	0-7	7-14	0-14
1	7970	253	310	369	57	59	116
2	7971	238	272	307	34	35	69
3	7972	242	305	361	63	56	119
4	7973	241	285	339	44	54	98
5	7974	234	273	313	39	40	79
Mean:		241.6	289.0	337.8	47.4	48.8	96.2
Standard deviation:		7.1	17.7	27.7	12.2	10.6	22.1

 

DOSE LEVEL: 2000mg/kgbw                                                                         SEX:FEMALE

Cage No.	Animal No.	Body weight (g) Days			Body Weight Gain (g)
		0	7	14	0-7	7-14	0-14
6	7985	264	276	298	12	22	34
7	7986	266	272	277	6	5	11
8	7987	256	270	279	14	9	23
9	7988	234	238	246	4	8	12
10	7989	219	257	260	38	3	41
Mean:		247.8	262.6	272.0	14.8	9.4	24.2
Standard deviation:		20.5	15.5	19.8	13.6	7.4	13.3

 

TABLE 3:            Macroscopic Findings

 

DOSE LEVEL: 2000mg/kgbw                                                                                      SEX:MALE

Cage No.	Animal No.	Necropsy Date/ Necropsy Day	External Observations	Internal Observations	Organ/ Tissue
1	7970	25 April 2017 Day 14	No external observations	No internal observations	Not applicable
2	7971	25 April 2017 Day 14	No external observations	No internal observations	Not applicable
3	7972	25 April 2017 Day 14	No external observations	No internal observations	Not applicable
4	7973	25 April 2017 Day 14	No external observations	No internal observations	Not applicable
5	7974	25 April 2017 Day 14	No external observations	No internal observations	Not applicable

 

DOSE LEVEL: 2000mg/kgbw                                                                                  SEX:FEMALE

 

Cage No.	Animal No.	Necropsy Date/ Necropsy Day	External Observations	Internal Observations	Organ/ Tissue
6	7985	25 April 2017 Day 14	No external observations	No internal observations	Not applicable
7	7986	25 April 2017 Day 14	No external observations	No internal observations	Not applicable
8	7987	25 April 2017 Day 14	No external observations	No internal observations	Not applicable
9	7988	25 April 2017 Day 14	No external observations	No internal observations	Not applicable
10	7989	25 April 2017 Day 14	No external observations	No internal observations	Not applicable

 

Interpretation of results:

GHS criteria not met

Conclusions:

The acute dermal median lethal dose (LD50) of the test item Sulfates of potassium, sodium and calcium, by-product from fermentation was found to be greater than 2000 mg/kg body weight in male and female Crl:WI rats. According to the CLP criteria, the test item was not classified for Acute Dermal Hazard.

Executive summary:

The purpose of this GLP compliant study was to assess the potential Acute Toxicity of the test substance Sulfates of potassium, sodium and calcium, by-product from fermentation, when applied dermally on Wistar rats, perfomed according to OECD 402 method.

A limit test  was  carried  out  at  2000 mg/kg  body  weight  (bw)  in  both sexes (5 rats/sex). The test item was powdered and was applied as a single dermal 24- hour exposure followed by a 14-day observation period.

Clinical observations were performed on all animals at 1 and 5 hours  after dosing and daily for 14 days thereafter. Body weight was measured prior to dosing on Day 0 and on Days 7 and 14 (before necropsy). Gross macroscopic examination was performed on all animals at the end of the 2-week observation period (Day 14).

Test item did not cause mortality at the dose level of 2000 mg/kg bw.

There were no systemic clinical signs noted in any animal throughout the study.

No adverse local dermal signs were observed after treatment with the test item or during the 14 days observation period.

There were no treatment related effects on body weight or body weight gain during the observation period.

There was no  evidence  of  any  macroscopic  changes  at  a  dose  level  of  2000 mg/kg bw.

The  acute  dermal  median  lethal  dose  (LD50)   of   the   test   item   Sulfates of potassium, sodium and calcium, by-product from fermentation was found to be greater than 2000 mg/kg body weight in male and female Crl:WI rats. According to the CLP criteria, the test item was not classified for Acute Dermal Hazard.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Quality of whole database:

GLP compliant study performed according to OECD guideline 402 (reliability 1)

Additional information

Acute toxicity: oral

No acute oral toxicity data is available for the substance Sulfates of potassium sodium and calcium, by-product from fermentation. However, data are available on the three sulfate salts: Sodium sulfate (CAS 7757-82-6), Potassium sulfate (CAS 7778-80-5) and Calcium Sulfate (CAS7778-18-9) and a read across approach was used to fulfill data requirement for this endpoint.

The read across approach is based on the results of the transformation/dissolution study performed on the registered substance (Envigo Research Limited, 2016). This study demonstrated that Sulfates of potassium sodium and calcium, by-product from fermentation is completely transformed/dissolved (98.1%) within 30 minutes at pH 2 and at 37 °C. Hence, upon systemic uptake into the body, the registered substance will be present in dissolved form as sulfate anions and potassium, sodium and calcium cations. Furthermore, the three salts Sodium sulfate, Potassium sulfate and Calcium Sulfate are also completely dissociated in aqueous media in Sulfate anions and the respective cations, then this justifies that toxicity data can be read across from the three salts Sulfates of potassium, Sulfates of sodium and Sulfates of calcium to the target substance for systemic toxicity endpoints.

A read across key study (OECD TG 420; NIER, 2003) is available for Calcium Sulfate (CAS 7778-18-9). Calcium sulfate dihydrate (CAS 10101-41-4) was administered to rats by gavage at 2000 mg/kg bw. No mortality and no systemic clinical signs were observed, so the oral LD50 for rats was > 2000 mg/kg bw. Based on this result, the calculated oral LD50 of Calcium sulfate anhydrous (CAS 7778-18-9) is >1581 mg/kg b.w. A key study (OECD 423; Harlan Laboratories LTD, 2010) is available for Sodium sulfate (CAS 7757-82-6). Rats were given the test item at 2000 mg/kg bw by oral gavage. The LD50 value was greater than 2000 mg/kg bw based on the absence of mortality or treatment related clinical signs. A read across key study (OECD TG 425; Product Safety Laboratories, 2000) is available for Potassium Sulfate (CAS 7778-80-5). Potassium magnesium sulphate (CAS 17855-14-0) was administered to rats by gavage at 2000 mg/kg bw. No mortality and no systemic clinical signs were observed, so the oral LD50 for rats was > 2000 mg/kg bw. Additionally, a reliability 4 supporting data (Secondary data sources) is also available on the Potassium Sulfate substance itself (International Uniform Chemical Information Database, 2000; Hazardous Substances Data Bank (HSDB), 1999; RTECS, 1999). An LD50 (rat) of 6600 mg/kg bw was found for Potassium Sulfate (i.e.  > 2000 mg/kg bw).

The results of the above acute oral toxicity studies are indicative of a similar low toxicity for the three analogue substances. Hence, based on these data and on the analogy approach, Sulfates of potassium, sodium and calcium, by-product from fermentation is not considered to be hazardous for acute oral toxicity (acute oral LD50 greater than 2000 mg/kg bw is attributed).

Acute toxicity: dermal

One GLP compliant study (OECD 402, Citoxlab, 2017) is available for evaluation of the Sulfates of potassium, sodium and calcium, by-product from fermentation, in which rats were treated with 2000 mg/kg bw of the substance by dermal route. The LD50 value was stated to be higher than this value due to absence of mortality.

Reliable experimental data for acute dermal toxicity is also available for the analogue Potassium sulfate (CAS 7778-80-5) (OECD 402, NOTOX B.V. 2010). Rats were exposed dermally to 2000 mg/kg bw for 24 hours. No mortality, body weight change abnormalities or gross pathology abnormalities were observed. Chromodacryorrhoea was noted in two males and one female on Day 1 and scales and scabs were noted in one male and one female between Day 5 and 11. Hence the LD50 value was determined to be greater than 2000 mg/kg bw. The very similar behavior of this analogue substance with the target substance for acute dermal effects further reinforces the read across justification applied for the systemic toxicity endpoints.

Acute toxicity: inhalation

Waiving for exposure considerations and scientifically unjustified

Justification: No data are available to evaluate the acute inhalation toxicity. According to column 2 part 8.5.2 of Annex VIII of REACh, the choice for the second route will depend on the nature of the substance and the likely route of human exposure. "Testing by the inhalation route is appropriate if exposure of humans via inhalation is likely, taking into account the vapour pressure of the substance and/or the possibility of exposure to aerosols, particles or droplets of an inhalable size". The test substance at room temperature is a solid made up of single crystalline particles. The melting point is > 400°C and thus, the vapor pressure determination does not need to be conducted (melting point is > 300°C). Based on these data, Sulfates of potassium sodium and calcium, by-product from fermentation is considered to have a low volatility potential. The substance has a Mass Median Aerodynamic Diameter (MMAD) of 378.181 µM with only 10 % of the test material particle size < 144.244 µM. According to Guidance on Information Requirements and Chemical Safety Assessment Chapter R.7a: Endpoint specific guidance (Version 6.0; July 2017), particles larger than 100 μM are less likely to be inhalable. Based on the overall physicochemical data, no exposure by inhalation is expected. Furthermore, the dermal route is the likely route of human exposure. According to the available dermal acute toxicity data, as well as the acute oral toxicity read across data, no toxic effects are expected and no test is required for the acute inhalation toxicity endpoint.

Justification for classification or non-classification

Acute Toxicity, oral: While no acute oral information is available for the target substance, all three read-across substances have acute oral LD50 values greater than 2000 mg/kg bw (in the rat). Based on the read-across rationale and the weight of evidence, the substance does not meet the criteria for classification according to Regulation (EC) No 1272/2008.

Acute Toxicity, dermal: reliable (GLP compliant; OECD Test Guideline 402) acute dermal toxicity data is available for the target substance. The results showed an acute dermal LD50 value greater than 2000 mg/kg bw in the rat (no mortality and no clinical signs). Based on this key study, the substance does not meet the criteria for classification according to Regulation (EC) No 1272/2008.

Acute Toxicity, inhalation: see waiving rationale in "Justification for type of information"

Specific Target Organ Toxicity– Single Exposure: Based on the data available on both the target substance and the read-across substances, the target substance is not likely to exhibit significant toxic effects arising from a single exposure. As a result, the substance does not meet the criteria for classification according to Regulation (EC) No 1272/2008.