Reaction mass of sulphuric acid, hydrogen peroxide and peroxomonosulphuric acid

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Link to relevant study records

Reference

Reference 1

Endpoint:

toxicity to reproduction

Remarks:

other: prenatal developmental toxicity study

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

no data

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The reaction mass of sulphuric acid, hydrogen peroxide and peroxomonosulphuric acid is predominantly sulphuric acid (>80%). Although all constituents of the reaction mass contribute towards and are essential for the desired technical effects of the range, it is considered acceptable to read-across to data on sulphuric acid. This because significant toxicological effects are likely to be masked in the multi-constituent substance by its corrosive nature and so it considered appropriate to read across to the mean constituent, sulphuric acid, when considering reproductive and developmental toxicity.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
See read-across data matrix under 'Attached background material' below.

3. ANALOGUE APPROACH JUSTIFICATION
See read-across data matrix under 'Attached background material' below.

4. DATA MATRIX
See read-across data matrix under 'Attached background material' below.

Qualifier:

equivalent or similar to guideline

Guideline:

other: OECD Guideline 414 (Prenatal Developmental Toxicity Study)

Deviations:

not specified

GLP compliance:

no

Remarks:

Study pre-dates GLP

Limit test:

no

Species:

rabbit

Strain:

New Zealand White

Sex:

male/female

Details on test animals or test system and environmental conditions:

- Nulliparous New Zealand White rabbits (Langshaws Rabbitry, Augusta, Michigan) were housed in wire-mesh cages
- Animals were housed in rooms designed to control temperature at 21 °C.
- Humidity was maintained at 45 %
- A cycle of 12 h light and 12 h dark was maintained.
- Animals were given free access to commercial laboratory chow (Ralston Purina Company, St Louis, Missouri) and tap water.
- Rabbits were acclimated to the environment for at least three weeks prior to commencement of the study.

Route of administration:

inhalation: aerosol

Type of inhalation exposure (if applicable):

whole body

Vehicle:

water

Details on exposure:

- Control animals were placed in chambers identical to those used for sulphuric acid exposure.
- Animals did not have access to food or water while in the exposure chambers.
- Exposures were conducted under dynamic airflow conditions in 4.3 m3 stainless steel and glass Rochester-type chambers.
- Chamber airflow was approximately 800 L/min.
- The aerosol was generated for each chamber by nebulising 2M sulphuric acid with a pneumatic atomising nozzle (Spraying System Company, Bellwood, Illinois)

Details on mating procedure:

- Female rabbits were artificially inseminated.
- The day on which artificial insemination took place in rabbits was considered to be day zero of gestation.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

- Sulphuric acid concentration in the exposure chambers was analysed three times per day throughout exposure with a column made of DOWEX 50W x 8 with a water eluent using a conductivity cell detector.
- Particle size of the aerosol was determined on four different exposure days using a particle size monitor (Royco instruments, Menlo park, California).
- The mean of the average time-weighted daily concentrations of sulphuric acid and the count median diameter of the sulphuric acid particles were recorded.

Duration of treatment / exposure:

- Day 6 to day 18 of gestation.

Frequency of treatment:

- Exposure took place for 7 h per day

Details on study schedule:

- Rabbits were sacrificed by carbon dioxide inhalation on day 29 of gestation.

Dose / conc.:

0 mg/m³ air (nominal)

Dose / conc.:

5 mg/m³ air (nominal)

Dose / conc.:

20 mg/m³ air (nominal)

No. of animals per sex per dose:

- 20 bred rabbits were exposed in each group.
- Twenty bred rabbits acted as vehicle controls and were exposed to filtered room air.

Control animals:

yes, sham-exposed

Parental animals: Observations and examinations:

- All animals were observed daily beginning on day 6 of gestation for indications of toxicity.
- Body weights were recorded on days 6, 9, 12, 15, 19 and 29 of gestation.

Litter observations:

- The number and position of live, dead and resorbed foetuses was noted.

Postmortem examinations (parental animals):

- The maternal liver was weighed.
- Respiratory tract tissues from 6 dams in each group were preserved in formalin and examined histologically.
- The nasal turbinates were decalcified and a section taken through a transverse plane.
- A minimum of 6 lung sections and a transverse section of trachea were taken from each rabbit.
- The tissues were processed by routine histologic procedures and stained with hematoxyylin and eosin prior to light microscopy.
- The uterus of each non-pregnant female was stained with a 10 % solution of sodium sulphide and examined for evidence of implantation sites.

Postmortem examinations (offspring):

- All foetuses were weighed, measured (crown-rump length), sexed, and examined for external alterations and cleft palate.
- One third of the foetuses from each litter were selected at random and immediately examined for evidence of soft tissue alterations by dissection under a stereo-microscope.
- All foetuses were cleared in KOH, stained with alizarin red-S and examinded for skeletal alterations.

Statistics:

- The Wilcoxon test as modified by Haseman and Hoel was used to evaluate the incidence of foetl alterations and resorptions.
- The litter was used as the experimental unit.
- Continuous data were analysed by one-way analysis of variance and Dunnett's test.
- The level of significance chosen for all cases was p < 0.05.

Clinical signs:

no effects observed

Description (incidence and severity):

inhalation of 5 mg/m3 or 20 mg/m3 of sulphuric acid did not alter the appearance of dams

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

statistically significant decrease in maternal body weight gain was noted during the first few days of exposure to 20 mg/m3 sulphuric acid

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

statistically significant decrease in maternal body weight gain was noted during the first few days of exposure to 20 mg/m3 sulphuric acid

Organ weight findings including organ / body weight ratios:

no effects observed

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

a trend towards dose related increase in the incidence of subacute rhinitis and tracheitis was noted

Other effects:

not examined

Reproductive function: oestrous cycle:

not examined

Reproductive function: sperm measures:

not examined

Reproductive performance:

no effects observed

Description (incidence and severity):

incidence of pregnancy and proportion of pregnancies detected by sodium sulphide stain was not significantly altered in comparison to the control group

- One control rabbit delivered a litter on day 28 of gestation.
- One rabbit from the 5 mg/m3 group delivered a litter on day 26 of gestation.

Dose descriptor:

LOAEC

Effect level:

19.3 mg/m³ air (analytical)

Based on:

test mat.

Sex:

female

Basis for effect level:

body weight and weight gain

food consumption and compound intake

histopathology: non-neoplastic

Dose descriptor:

NOEC

Effect level:

5.7 mg/m³ air (analytical)

Based on:

test mat.

Sex:

female

Basis for effect level:

body weight and weight gain

food consumption and compound intake

histopathology: non-neoplastic

Clinical signs:

not examined

Mortality / viability:

not examined

Body weight and weight changes:

not examined

Sexual maturation:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

not examined

Histopathological findings:

not examined

- The mean numbers of implants per dam, live foetuses per litter, or resorptions per litter were not significantly altered by exposure.
- No significant effect on foetal sex ratio was seen,
- Mean weights and lengths of offspring were not significantly altered from their respective control values.

Generation:

F1

Remarks on result:

not determinable due to absence of adverse toxic effects

Reproductive effects observed:

not specified

JUSTIFICATION FOR USE OF READ-ACROSS DATA

See comparison of overall physico-chemical and toxicity profiles for target and source chemicals in the data matrix (attached)

CONCENTRATION AND PARTICLE SIZE OF SULPHURIC ACID IN THE CHAMBERS

		Sulphuric acid (mg/m3)
		Zero	5	20
Analytical concentration		Not determined	5.7±1.2	19.3±4.0
Particle size (count median diameter ± geometric standard deviation)		0.4*	1.6±2.6	2.4±2.7
Percent of particles with a diameter of less than:
0.4		84.5	27.5	19.3
1.0		88.8	34.5	21.3
2.2		90.6	66.3	52.0
4.0		91.3	94.8	77.6
7.5		100.0	100.0	100.0
Total number of particle counts used to determine particle size		616,005	5,259,714	3,733,690
Relative humidity (%)**		44 ± 7	52±5	56±5
Temperature (°C)**		22 ± 1	22±1	21±1
*	This figure represents the airborne dust in the chamber
**	Mean ± standard deviation

Conclusions:

Although slight maternal toxicity was seen when rabbits were exposed to 20 mg/m3 sulphuric acid, no other evidence of reproductive toxicity was noted under the conditions of the investigation.

Reference 2

Endpoint:

reproductive toxicity, other

Remarks:

other: prenatal developmental toxicity study

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

no data

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The reaction mass of sulphuric acid, hydrogen peroxide and peroxomonosulphuric acid is predominantly sulphuric acid (>80%). Although all constituents of the reaction mass contribute towards and are essential for the desired technical effects of the range, it is considered acceptable to read-across to data on sulphuric acid. This because significant toxicological effects are likely to be masked in the multi-constituent substance by its corrosive nature and so it considered appropriate to read across to the mean constituent, sulphuric acid, when considering reproductive and developmental toxicity.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
See read-across data matrix under 'Attached background material' below.

3. ANALOGUE APPROACH JUSTIFICATION
See read-across data matrix under 'Attached background material' below.

4. DATA MATRIX
See read-across data matrix under 'Attached background material' below.

Qualifier:

equivalent or similar to guideline

Guideline:

other: OECD Guideline 414 (Prenatal Developmental Toxicity Study)

Deviations:

not specified

GLP compliance:

no

Remarks:

Study pre-dates GLP

Limit test:

no

Species:

mouse

Strain:

CF-1

Sex:

male/female

Details on test animals or test system and environmental conditions:

- Nulliparous CF-1 mice (Charles River, Portgage, Michigan) were housed in wire-mesh cages
- Animals were housed in rooms designed to control temperature at 21 °C.
- Humidity was maintained at 45 %
- A cycle of 12 h light and 12 h dark was maintained.
- Animals were given free access to commercial laboratory chow (Ralston Purina Company, St Louis, Missouri) and tap water.
- Mice were acclimated to the environment for at least two weeks prior to commencement of the study.

Route of administration:

inhalation: aerosol

Type of inhalation exposure (if applicable):

whole body

Vehicle:

water

Details on exposure:

- Control animals were placed in chambers identical to those used for sulphuric acid exposure.
- Animals did not have access to food or water while in the exposure chambers.
- Exposures were conducted under dynamic airflow conditions in 4.3 m3 stainless steel and glass Rochester-type chambers.
- Chamber airflow was approximately 800 L/min.
- The aerosol was generated for each chamber by nebulising 2M sulphuric acid with a pneumatic atomising nozzle (Spraying System Company, Bellwood, Illinois)

Details on mating procedure:

- Female mice were pen-bred with fertile males of the same strain.
- The day on which a vaginal plug was observed in mice was considered to be day zero of gestation.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

- Sulphuric acid concentration in the exposure chambers was analysed three times per day throughout exposure with a column made of DOWEX 50W x 8 with a water eluent using a conductivity cell detector.
- Particle size of the aerosol was determined on four different exposure days using a particle size monitor (Royco instruments, Menlo park, California).
- The mean of the average time-weighted daily concentrations of sulphuric acid and the count median diameter of the sulphuric acid particles were recorded.

Duration of treatment / exposure:

- Day 6 to day 15 of gestation.

Frequency of treatment:

- Exposure took place for 7 h per day

Details on study schedule:

- Mice were sacrificed by carbon dioxide inhalation on day 18 of gestation.

Dose / conc.:

0 mg/m³ air (nominal)

Dose / conc.:

5 mg/m³ air (nominal)

Dose / conc.:

20 mg/m³ air (nominal)

No. of animals per sex per dose:

- 35 bred were mice exposed in each group.
- Forty bred mice acted as vehicle controls and were exposed to filtered room air.

Control animals:

yes, sham-exposed

Parental animals: Observations and examinations:

- All animals were observed daily beginning on day 6 of gestation for indications of toxicity.
- Body weights were recorded on days 6, 8, 10, 16 and 18 of gestation.
- Consumption of food and water was measured at three day intervals.

Litter observations:

- The number and position of live, dead and resorbed foetuses was noted.
- The heads of mice examined internally were placed in Bouin's solution and examined by the razor-section technique.

Postmortem examinations (parental animals):

- The maternal liver was weighed.
- Respiratory tract tissues from 6 dams in each group were preserved in formalin and examined histologically.
- The nasal turbinates were decalcified and a section taken through a transverse plane.
- The entire lung, trachea, oesophagus, and mediastinal tissues were embedded as a unit and sectioned for microscopic evaluation.
- The tissues were processed by routine histologic procedures and stained with hematoxyylin and eosin prior to light microscopy.
- The uterus of each non-pregnant female was stained with a 10 % solution of sodium sulphide and examined for evidence of implantation sites.

Postmortem examinations (offspring):

- All foetuses were weighed, measured (crown-rump length), sexed, and examined for external alterations and cleft palate.
- One third of the foetuses from each litter were selected at random and immediately examined for evidence of soft tissue alterations by dissection under a stereo-microscope.
- All foetuses were cleared in KOH, stained with alizarin red-S and examinded for skeletal alterations.

Statistics:

- The Wilcoxon test as modified by Haseman and Hoel was used to evaluate the incidence of foetl alterations and resorptions.
- The litter was used as the experimental unit.
- Continuous data were analysed by one-way analysis of variance and Dunnett's test.
- The level of significance chosen for all cases was p < 0.05.

Clinical signs:

no effects observed

Description (incidence and severity):

inahlation of 5 mg/m3 or 20 mg/m3 of sulphuric acid did not alter the appearance of dams

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

body weight gain was not significantly less than that of controls although a decrease in food consumed was noted in the first few days at 20 mg/m3 but not at 5 mg/m3

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

body weight gain was not significantly less than that of controls although a decrease in food consumed was noted in the first few days at 20 mg/m3 but not at 5 mg/m3

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Histopathological findings: non-neoplastic:

no effects observed

Description (incidence and severity):

microscopic examination of nasal turbinates, trachea, and lungs revealed no evidence of toxicity that could be attributed to sulphuric acid

Other effects:

not examined

Reproductive function: oestrous cycle:

not examined

Reproductive function: sperm measures:

not examined

Reproductive performance:

no effects observed

Description (incidence and severity):

incidence of pregnancy and proportion of pregnancies detected by sodium sulphide stain was not significantly altered in comparison to the control group

Dose descriptor:

LOAEC

Effect level:

19.3 mg/m³ air (analytical)

Based on:

test mat.

Sex:

female

Basis for effect level:

body weight and weight gain

organ weights and organ / body weight ratios

Dose descriptor:

NOAEC

Effect level:

5.7 mg/m³ air (analytical)

Based on:

test mat.

Sex:

female

Basis for effect level:

body weight and weight gain

organ weights and organ / body weight ratios

Clinical signs:

not examined

Mortality / viability:

not examined

Body weight and weight changes:

not examined

Sexual maturation:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

not examined

Histopathological findings:

not examined

- The mean numbers of implants per dam, live foetuses per litter, or resorptions per litter were not significantly altered by exposure.
- No significant effect on foetal sex ratio was seen,
- Mean weights and lengths of offspring were not significantly altered from their respective control values.

Generation:

F1

Remarks on result:

not determinable due to absence of adverse toxic effects

Reproductive effects observed:

not specified

JUSTIFICATION FOR USE OF READ-ACROSS DATA

See comparison of overall physico-chemical and toxicity profiles for target and source chemicals in the data matrix (attached)

CONCENTRATION AND PARTICLE SIZE OF SULPHURIC ACID IN THE CHAMBERS

		Sulphuric acid (mg/m3)
		Zero	5	20
Analytical concentration		Not determined	5.7±1.2	19.3±4.0
Particle size (count median diameter ± geometric standard deviation)		0.4*	1.6±2.6	2.4±2.7
Percent of particles with a diameter of less than:
0.4		84.5	27.5	19.3
1.0		88.8	34.5	21.3
2.2		90.6	66.3	52.0
4.0		91.3	94.8	77.6
7.5		100.0	100.0	100.0
Total number of particle counts used to determine particle size		616,005	5,259,714	3,733,690
Relative humidity (%)**		44 ± 7	52±5	56±5
Temperature (°C)**		22 ± 1	22±1	21±1
*	This figure represents the airborne dust in the chamber
**	Mean ± standard deviation

Conclusions:

Although slight maternal toxicity was seen when mice were exposed to 20 mg/m3 sulphuric acid, no other evidence of reproductive toxicity was noted under the conditions of the investigation.

Effect on fertility: via oral route

Endpoint conclusion:

no study available

Effect on fertility: via inhalation route

Endpoint conclusion:

no adverse effect observed

Effect on fertility: via dermal route

Endpoint conclusion:

no study available

Additional information

Short description of key information:
No effects on fertility were seen in mice or rabbits exposed to sulphuric acid via the inhalation route during a study focusing on developmental toxicity. As such, further investigation is considered unnecessary because the multi-constituent test material is classified as corrosive to skin and is used only under modern industrial conditions where rigorous training and appropriate risk management measures can be expected to prevent exposure via the oral, dermal or inhalation routes.

Justification for selection of Effect on fertility via oral route:
The multi-constituent test material is classified as corrosive to skin and is used only under modern industrial conditions where rigorous training and appropriate risk management measures are assumed to avoid oral exposure. As a result, and in accordance with Regulation (EC) 1907/2006, Annex IX, section 8.7.3, column 2, systemic absorption can be discounted and investigation of reproductive toxicity via the oral route is unnecessary.

Justification for selection of Effect on fertility via inhalation route:
No evidence of reduced fertility was seen when two species (mice and rabbits) were exposed to sulphuric acid, which is the main component of the multi-constituent test material, under the same conditions, during a study focusing on developmental toxicity. Furthermore, the multi-constituent test material is designed to be highly corrosive, local effects will override systemic absorption leading to toxicity, and it is considered unnecessary to subject vertebrate animals to a two-generation reproductive toxicity study via the inhalation route.

Justification for selection of Effect on fertility via dermal route:
The multi-constituent test material is classified as corrosive to skin and is used only under modern industrial conditions where rigorous training and appropriate risk management measures are assumed to avoid dermal exposure. As a result, and in accordance with Regulation (EC) 1907/2006, Annex IX, section 8.7.3, column 2, systemic absorption can be discounted and investigation of reproductive toxicity via the dermal route is unnecessary.

Effects on developmental toxicity

Description of key information

Embryotoxicity and teratogenic effects were considered to be absent when mice or rabbits were exposed to sulphuric acid via the inhalation route. A such, further investigation is considered unnecessary because the multi-constituent test material is classified as corrosive to skin and is used only under modern industrial conditions where rigorous training and appropriate risk management measures can be expected to prevent exposure via the oral, dermal or inhalation routes.

Link to relevant study records

Reference

Reference 1

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

no data

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The reaction mass of sulphuric acid, hydrogen peroxide and peroxomonosulphuric acid is predominantly sulphuric acid (>80%). Although all constituents of the reaction mass contribute towards and are essential for the desired technical effects of the range, it is considered acceptable to read-across to data on sulphuric acid. This because significant toxicological effects are likely to be masked in the multi-constituent substance by its corrosive nature and so it considered appropriate to read across to the mean constituent, sulphuric acid, when considering reproductive and developmental toxicity.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
See read-across data matrix under 'Attached background material' below.

3. ANALOGUE APPROACH JUSTIFICATION
See read-across data matrix under 'Attached background material' below.

4. DATA MATRIX
See read-across data matrix under 'Attached background material' below.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

Deviations:

not specified

GLP compliance:

no

Remarks:

Study pre-dates GLP

Limit test:

no

Species:

mouse

Strain:

CF-1

Details on test animals or test system and environmental conditions:

- Nulliparous CF-1 mice (Charles River, Portgage, Michigan) were housed in wire-mesh cages
- Animals were housed in rooms designed to control temperature at 21 °C.
- Humidity was maintained at 45 %
- A cycle of 12 h light and 12 h dark was maintained.
- Animals were given free access to commercial laboratory chow (Ralston Purina Company, St Louis, Missouri) and tap water.
- Mice were acclimated to the environment for at least two weeks prior to commencement of the study.

Route of administration:

inhalation: aerosol

Type of inhalation exposure (if applicable):

whole body

Vehicle:

water

Details on exposure:

- Control animals were placed in chambers identical to those used for sulphuric acid exposure.
- Animals did not have access to food or water while in the exposure chambers.
- Exposures were conducted under dynamic airflow conditions in 4.3 m3 stainless steel and glass Rochester-type chambers.
- Chamber airflow was approximately 800 L/min.
- The aerosol was generated for each chamber by nebulising 2M sulphuric acid with a pneumatic atomising nozzle (Spraying System Company, Bellwood, Illinois)

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

- Sulphuric acid concentration in the exposure chambers was analysed three times per day throughout exposure with a column made of DOWEX 50W x 8 with a water eluent using a conductivity cell detector.
- Particle size of the aerosol was determined on four different exposure days using a particle size monitor (Royco instruments, Menlo park, California).
- The mean of the average time-weighted daily concentrations of sulphuric acid and the count median diameter of the sulphuric acid particles were recorded.

Details on mating procedure:

- Female mice were pen-bred with fertile males of the same strain.
- The day on which a vaginal plug was observed in mice was considered to be day zero of gestation.

Duration of treatment / exposure:

- Day 6 to day 15 of gestation.

Frequency of treatment:

- Exposure took place for 7 h per day

Duration of test:

- Length of normal pregnancy

No. of animals per sex per dose:

- 35 bred were mice exposed in each group.
- Forty bred mice acted as vehicle controls and were exposed to filtered room air.

Control animals:

yes, sham-exposed

Details on study design:

- Mice were sacrificed by carbon dioxide inhalation on day 18 of gestation.

Maternal examinations:

- All animals were observed daily beginning on day 6 of gestation for indications of toxicity.
- Body weights were recorded on days 6, 8, 10, 16 and 18 of gestation.
- Consumption of food and water was measured at three day intervals.

Ovaries and uterine content:

- The uterus of each non-pregnant female was stained with a 10 % solution of sodium sulphide and examined for evidence of implantation sites.

Fetal examinations:

- The number and position of live, dead and resorbed foetuses was noted.
- The heads of mice examined internally were placed in Bouin's solution and examined by the razor-section technique.
- All foetuses were weighed, measured (crown-rump length), sexed, and examined for external alterations and cleft palate.
- One third of the foetuses from each litter were selected at random and immediately examined for evidence of soft tissue alterations by dissection under a stereo-microscope.
- All foetuses were cleared in KOH, stained with alizarin red-S and examinded for skeletal alterations.

Statistics:

- The Wilcoxon test as modified by Haseman and Hoel was used to evaluate the incidence of foetl alterations and resorptions.
- The litter was used as the experimental unit.
- Continuous data were analysed by one-way analysis of variance and Dunnett's test.
- The level of significance chosen for all cases was p < 0.05.

Historical control data:

- Several cases of exencephaly were noted among exposed mice. However, the incidence of this malformation in the experimental groups was not inconsistent with that seen among control groups in other studies conducted in the same laboratory.

Details on maternal toxic effects:

Details on maternal toxic effects:
- Inhalation of 5 mg/m3 or 20 mg/m3 sulphuric acid did not alter the appearance of dams.
- Compared to the control group, the incidence of pregnancy, as well as the proportion of pregnancies detected by sodium sulphide stain, was not significantly altered.
- Body weight gain of mice exposed to sulphuric acid was not significantly less than that of the control group.
- A significant decrease in the amount of food consumed during the first few days of exposure was observed at 20 mg/m3 but not at 5 mg/m3.
- At sacrifice, the liver weight (absolute and relative) of pregnant mice exposed to 20 mg/m3 was significantly less than that of the controls.
- Gross and microscopic examination of the nasal turbinates, trachea, and lungs of mice revealed no evidence of toxicity that could be attributed to sulphuric acid.

Dose descriptor:

NOAEC

Effect level:

19.3 mg/m³ air (analytical)

Based on:

test mat.

Basis for effect level:

other: developmental toxicity

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effects

Details on embryotoxic / teratogenic effects:
- Exposure of mice to sulphuric acid did not significantly alter the mean numbers of implants per dam, live foetuses per litter, or resorptions per litter.
- No significant effect on foetal sex ratio was seen in mice.
- Mean body weights and lengths of the offspring of mice exposed to sulphuric acid were not significantly different from the controls.
- Whether considered individually or collectively, offspring of mice exposed to sulphuric acid did not have significantly higher incidence of malformations than the controls.
- In the 20 mg/m3 group, two foetuses were conjoined ventrally through the head, neck and thoracic regions. One of the conjoined heads had exencephaly, ablepharis and cleft palate; the other head was micrognathic and lacked an oral opening. Although the occurrance of conjoined foetuses is extremely rare, one case was not considered sufficient evidence to conclude that sulphuric acid was teratogenic.
- Inhalation of sulphuric acid did not increase the incidence of minor skeletal variants among the offspring of exposed mice.

Dose descriptor:

NOAEC

Effect level:

19.3 mg/L air (analytical)

Based on:

test mat.

Basis for effect level:

other: teratogenicity

Abnormalities:

not specified

Developmental effects observed:

not specified

JUSTIFICATION FOR USE OF READ-ACROSS DATA

See comparison of overall physico-chemical and toxicity profiles for target and source chemicals in the data matrix (attached)

CONCENTRATION AND PARTICLE SIZE OF SULPHURIC ACID IN THE CHAMBERS

		Sulphuric acid (mg/m3)
		Zero	5	20
Analytical concentration		Not determined	5.7 ± 1.2	19.3 ± 4.0
Particle size (count median diameter ± geometric standard deviation)		0.4*	1.6 ± 2.6	2.4 ± 2.7
Percent of particles with a diameter of less than:
0.4		84.5	27.5	19.3
1.0		88.8	34.5	21.3
2.2		90.6	66.3	52.0
4.0		91.3	94.8	77.6
7.5		100.0	100.0	100.0
Total number of particle counts used to determine particle size		616,005	5,259,714	3,733,690
Relative humidity (%)**		44 ± 7	52 ± 5	56 ± 5
Temperature (°C)**		22 ± 1	22 ± 1	21 ± 1
*	This figure represents the airborne dust in the chamber
**	Mean ± standard deviation

Conclusions:

Although slight maternal toxicity was seen at 20 mg/m3, little evidence of embryotoxicity was observed in mice exposed to 5 mg/m3 or 20 mg/m3 sulphuric acid for 7 h per day and a teratogenic effect was not detected.

Reference 2

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

no data

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The reaction mass of sulphuric acid, hydrogen peroxide and peroxomonosulphuric acid is predominantly sulphuric acid (>80%). Although all constituents of the reaction mass contribute towards and are essential for the desired technical effects of the range, it is considered acceptable to read-across to data on sulphuric acid. This because significant toxicological effects are likely to be masked in the multi-constituent substance by its corrosive nature and so it considered appropriate to read across to the mean constituent, sulphuric acid, when considering reproductive and developmental toxicity.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
See read-across data matrix under 'Attached background material' below.

3. ANALOGUE APPROACH JUSTIFICATION
See read-across data matrix under 'Attached background material' below.

4. DATA MATRIX
See read-across data matrix under 'Attached background material' below.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

Deviations:

not specified

GLP compliance:

no

Remarks:

Study pre-dates GLP

Limit test:

no

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

- Nulliparous New Zealand White rabbits (Langshaws Rabbitry, Augusta, Michigan) were housed in wire-mesh cages
- Animals were housed in rooms designed to control temperature at 21 °C.
- Humidity was maintained at 45 %
- A cycle of 12 h light and 12 h dark was maintained.
- Animals were given free access to commercial laboratory chow (Ralston Purina Company, St Louis, Missouri) and tap water.
- Rabbits were acclimated to the environment for at least three weeks prior to commencement of the study.

Route of administration:

inhalation: aerosol

Type of inhalation exposure (if applicable):

whole body

Vehicle:

water

Details on exposure:

- Control animals were placed in chambers identical to those used for sulphuric acid exposure.
- Animals did not have access to food or water while in the exposure chambers.
- Exposures were conducted under dynamic airflow conditions in 4.3 m3 stainless steel and glass Rochester-type chambers.
- Chamber airflow was approximately 800 L/min.
- The aerosol was generated for each chamber by nebulising 2M sulphuric acid with a pneumatic atomising nozzle (Spraying System Company, Bellwood, Illinois)

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

- Sulphuric acid concentration in the exposure chambers was analysed three times per day throughout exposure with a column made of DOWEX 50W x 8 with a water eluent using a conductivity cell detector.
- Particle size of the aerosol was determined on four different exposure days using a particle size monitor (Royco instruments, Menlo park, California).
- The mean of the average time-weighted daily concentrations of sulphuric acid and the count median diameter of the sulphuric acid particles were recorded.

Details on mating procedure:

- Female rabbits were artificially inseminated.
- The day on which artificial insemination took place in rabbits was considered to be day zero of gestation.

Duration of treatment / exposure:

- Day 6 to day 18 of gestation.

Frequency of treatment:

- Exposure took place for 7 h per day.

Duration of test:

- Length of normal pregnancy

No. of animals per sex per dose:

- 20 bred rabbits were exposed in each group.
- Twenty bred rabbits acted as vehicle controls and were exposed to filtered room air

Control animals:

yes, sham-exposed

Details on study design:

- Rabbits were sacrificed by carbon dioxide inhalation on day 29 of gestation.

Maternal examinations:

- All animals were observed daily beginning on day 6 of gestation for indications of toxicity.
- Body weights were recorded on days 6, 9, 12, 15, 19 and 29 of gestation.

Ovaries and uterine content:

- The uterus of each non-pregnant female was stained with a 10 % solution of sodium sulphide and examined for evidence of implantation sites.

Fetal examinations:

- The number and position of live, dead and resorbed foetuses was noted.
- All foetuses were weighed, measured (crown-rump length), sexed, and examined for external alterations and cleft palate.
- One third of the foetuses from each litter were selected at random and immediately examined for evidence of soft tissue alterations by dissection under a stereo-microscope.
- All foetuses were cleared in KOH, stained with alizarin red-S and examinded for skeletal alterations.

Statistics:

- The Wilcoxon test as modified by Haseman and Hoel was used to evaluate the incidence of foetl alterations and resorptions.
- The litter was used as the experimental unit.
- Continuous data were analysed by one-way analysis of variance and Dunnett's test.
- The level of significance chosen for all cases was p < 0.05.

Details on maternal toxic effects:

Maternal toxic effects:yes

Details on maternal toxic effects:
- A statistically significant decrease in maternal body weight gain was noted during the first few days of exposure to 20 mg/m3 sulphuric acid.
- The liver weight of the rabbits at sacrifice was unaltered by exposure to sulphuric acid.
- Histologic examination of the nasal turbinates, trachea, and lungs revealed a trend towards a dose-related increase in the incidence of subacute rhinitis and tracheitis.
- No changes were seen in the lungs that were considered to be due to sulphuric acid exposure.

Dose descriptor:

NOAEC

Effect level:

19.3 mg/m³ air (analytical)

Based on:

test mat.

Basis for effect level:

other: developmental toxicity

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effects

Details on embryotoxic / teratogenic effects:
- In rabbits, the incidence of foetal malformations, considered individually or collectively, was not significantly altered by exposure to sulphuric acid.
- The only statistically significant evidence of embryotoxicity in rabbits was an increased incidence of small non-ossified areas in the skull bones (a minor variation in skeletal development) among the offspring of does exposed to 20 mg/m3.

Dose descriptor:

NOAEC

Effect level:

19.3 mg/m³ air (analytical)

Based on:

test mat.

Basis for effect level:

other: teratogenicity

Abnormalities:

not specified

Developmental effects observed:

not specified

JUSTIFICATION FOR USE OF READ-ACROSS DATA

See comparison of overall physico-chemical and toxicity profiles for target and source chemicals in the data matrix (attached)

CONCENTRATION AND PARTICLE SIZE OF SULPHURIC ACID IN THE CHAMBERS

		Sulphuric acid (mg/m3)
		Zero	5	20
Analytical concentration		Not determined	5.7±1.2	19.3±4.0
Particle size (count median diameter ± geometric standard deviation)		0.4*	1.6±2.6	2.4±2.7
Percent of particles with a diameter of less than:
0.4		84.5	27.5	19.3
1.0		88.8	34.5	21.3
2.2		90.6	66.3	52.0
4.0		91.3	94.8	77.6
7.5		100.0	100.0	100.0
Total number of particle counts used to determine particle size		616,005	5,259,714	3,733,690
Relative humidity (%)**		44 ± 7	52±5	56±5
Temperature (°C)**		22 ± 1	22±1	21±1
*	This figure represents the airborne dust in the chamber
**	Mean ± standard deviation

Conclusions:

Although slight maternal toxicity was seen at 20 mg/m3, little evidence of embryotoxicity was observed in rabbits exposed to 5 mg/m3 or 20 mg/m3 sulphuric acid for 7 h per day and a teratogenic effect was not detected.

Effect on developmental toxicity: via oral route

Endpoint conclusion:

no study available

Effect on developmental toxicity: via inhalation route

Endpoint conclusion:

no adverse effect observed

Effect on developmental toxicity: via dermal route

Endpoint conclusion:

no study available

Additional information

Justification for selection of Effect on developmental toxicity: via oral route:
The multi-constituent test material is classified as corrosive to skin and is used only under modern industrial conditions where rigorous training and appropriate risk management measures are assumed to avoid oral exposure. As a result, and in accordance with Regulation (EC) 1907/2006, Annex IX, section 8.7.2, column 2, systemic absorption can be discounted and investigation of prenatal developmental toxicity via the oral route is unnecessary.

Justification for selection of Effect on developmental toxicity: via inhalation route:
Embryotoxicity and teratogenic effects were considered to be absent when two species (mice and rabbits) were exposed to sulphuric acid, which is the main component of the multi-constituent test material, under the same conditions. Furthermore, the multi-constituent test material is designed to be highly corrosive, local effects will override systemic absorption leading to toxicity, and it is considered unnecessary to subject vertebrate animals to a prenatal developmental toxicity study via the inhalation route.

Justification for selection of Effect on developmental toxicity: via dermal route:
The multi-constituent test material is classified as corrosive to skin and is used only under modern industrial conditions where rigorous training and appropriate risk management measures are assumed to avoid dermal exposure. As a result, and in accordance with Regulation (EC) 1907/2006, Annex IX, section 8.7.2, column 2, systemic absorption can be discounted and investigation of prenatal developmental toxicity via the dermal route is unnecessary.

Justification for classification or non-classification

Evidence of reproductive toxicity, embryotoxicity and teratogenic effects were absent when two species (mice and rabbits) were exposed to sulphuric acid via the inhalation route. Furthermore, the multi-constituent test material is classified as corrosive to skin and is used only under modern industrial conditions where rigorous training and appropriate risk management measures can be expected to prevent exposure via the oral, dermal or inhalation routes. For these reasons it is considered unnecessary to classify the multi-constituent test material, which consists of > 80 % sulphuric acid, under the terms of Directive 67/548/EEC or GHS as reflected by Regulation (EC) 1272/2008.