Registration Dossier

Data platform availability banner - registered substances factsheets

Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

Description of key information

Test data on irritation properties of synthetic amorphous silica that have been used for read-across do not show eye or skin irritation.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Referenceopen allclose all

Endpoint:
skin irritation: in vivo
Type of information:
experimental study
Adequacy of study:
key study
Study period:
09 - 19 Oct. 1990
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP guideline study
Qualifier:
according to guideline
Guideline:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
GLP compliance:
yes
Species:
rabbit
Strain:
other: White Russian
Type of coverage:
occlusive
Preparation of test site:
shaved
Vehicle:
water
Controls:
no
Amount / concentration applied:
Dose: 0.5 g
Duration of treatment / exposure:
4 hour(s)
Observation period:
14 days
Number of animals:
3
Details on study design:
The substance (0.5 g) was moistened with 0.5 ml water and placed on a skin area of approx 6.25 cm2.
Irritation parameter:
primary dermal irritation index (PDII)
Basis:
animal #1
Remarks:
ID Nr. 2330
Time point:
other: 1 h after exposure
Score:
>= 0
Max. score:
0
Reversibility:
other: no irritation observed
Remarks on result:
no indication of irritation
Irritation parameter:
primary dermal irritation index (PDII)
Basis:
animal #2
Remarks:
ID Nr. 2332
Time point:
other: 1 h after exposure
Score:
>= 0
Max. score:
0
Reversibility:
other: no irritation observed
Remarks on result:
no indication of irritation
Irritation parameter:
primary dermal irritation index (PDII)
Basis:
animal #3
Remarks:
ID Nr. 2344
Time point:
other: 1 h after exposure
Score:
>= 0
Max. score:
0
Reversibility:
other: no irritation observed
Remarks on result:
no indication of irritation
Irritation parameter:
primary dermal irritation index (PDII)
Basis:
animal #1
Remarks:
ID Nr. 2330
Time point:
24/48/72 h
Score:
>= 0
Max. score:
0
Reversibility:
other: no irritation observed
Remarks on result:
no indication of irritation
Irritation parameter:
primary dermal irritation index (PDII)
Basis:
animal #2
Remarks:
ID Nr. 2332
Time point:
24/48/72 h
Score:
>= 0
Max. score:
0
Reversibility:
other: no irritation observed
Remarks on result:
no indication of irritation
Irritation parameter:
primary dermal irritation index (PDII)
Basis:
animal #3
Remarks:
ID Nr. 2344
Time point:
24/48/72 h
Score:
> 0
Max. score:
0
Reversibility:
other: no irritation observed
Remarks on result:
no indication of irritation
Irritant / corrosive response data:
There were not any irritating effects.

No signs of irritation.

Interpretation of results:
GHS criteria not met
Conclusions:
No classification (EU and GHS)
Executive summary:

Jahn and Berthold (1991) studied skin irritation of precipitated silica on rabbits by the OECD 404 guideline test method. No irritating effects were observed.

Endpoint:
skin irritation: in vivo
Type of information:
other: other: OECD evaluation of an in vivo skin irritation study
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: A scientific review by authorative international body
Reason / purpose for cross-reference:
reference to same study
Principles of method if other than guideline:
OECD evaluated the available test data on synthetic amorphous silica.
GLP compliance:
no
Remarks:
review: both yes and no status
Species:
rabbit
Irritation parameter:
erythema score
Basis:
mean
Time point:
other: 24 hours
Score:
>= 0 - <= 0.29
Reversibility:
fully reversible within: 72 h
Remarks on result:
other: hydrophilic precipitated silica; slight erythemas in 4/6 animals
Irritant / corrosive response data:
The studies with synthetic amorphous silica presented in the OECD SIDS (2004) did not indicate that the substance is a skin irritant.
Interpretation of results:
GHS criteria not met
Conclusions:
OECD (2004) includes eight skin irritation studies, of which three were regarded as critical studies for SIDS endpoint. These three studies were conducted with hydrophilic pyrogenic or precipitated silica. None of the studies showed skin irritating effects.
Executive summary:

In OECD (2004), hydrophilic pyrogenic or precipitated silica were tested by exposing rabbits to 0.19 g or 0.5 g of dry or moistened test item under occlusive conditions for 4 or 24 hours. These synthetic amorphous silica were not irritating to skin under experimental conditions. However, these compounds may produce skin dryness following prolonged and repeated exposure.

Endpoint:
skin irritation: in vivo
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
weight of evidence
Justification for type of information:
No toxicological data were available for silica fume and, therefore, a read-across approach was used. The dissolution, composition and surface properties were the most important parameters considered when deciding which substances can be used for read-across.

Based on the composition, surface characteristics, and bioaccessibility data, silica fume was assumed to have toxicological properties similar to those of sparingly synthetic amorphous silicas. Therefore read-across was carried out using available toxicological studies with synthetic amorphous silica (SAS).

Details on the read-across approach are presented in Iuclid section 13.
Reason / purpose for cross-reference:
read-across source
Reason / purpose for cross-reference:
read-across source
Remarks on result:
no indication of irritation
Irritation parameter:
other: Weight of evidence of read-across studies
Basis:
other: Different parameters followed in the other studies.
Score:
>= 0 - <= 0.29
Reversibility:
fully reversible
Remarks on result:
no indication of irritation
Interpretation of results:
GHS criteria not met
Conclusions:
No indications of skin irritation observed in studies with synthetic amorphous silica.
Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Referenceopen allclose all

Endpoint:
eye irritation: in vivo
Type of information:
experimental study
Adequacy of study:
key study
Study period:
22 Oct. - 05 Nov 1990
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to guideline
Guideline:
OECD Guideline 405 (Acute Eye Irritation / Corrosion)
GLP compliance:
yes
Species:
rabbit
Strain:
other: White Russian
Vehicle:
unchanged (no vehicle)
Controls:
not required
Amount / concentration applied:
dose: 100 mg
Duration of treatment / exposure:
24 h, not rinsed
Observation period (in vivo):
7 days
Number of animals or in vitro replicates:
3
Details on study design:
Comment: not rinsed
REMOVAL OF TEST SUBSTANCE
- Washing (if done): not rinsed
- Time after start of exposure: 24 h


SCORING SYSTEM: Intensities of irritation effects by using the Draize scale for grading of lesions (scores 0 - 4).
Irritation index: calculated according to Draize from grades on cornea, iris and conjunctiva at the time 1, 24, 48 and 72 h,
modified according to Gilman et al. 1983


Irritation parameter:
other: Draize Grades
Remarks:
Conjunctiva: redness, chemosis, discharge
Basis:
animal #1
Remarks:
ID Nr. 2303
Time point:
other: 1 h after application
Score:
ca. 2
Max. score:
2
Reversibility:
fully reversible within: 48 h
Remarks on result:
no indication of irritation
Irritation parameter:
other: Draize Grades
Remarks:
Conjunctiva: redness, chemosis, discharge
Basis:
animal #2
Remarks:
ID Nr. 2331
Time point:
other: 1 h after application
Score:
ca. 2
Max. score:
2
Reversibility:
fully reversible within: 4 days
Remarks on result:
no indication of irritation
Irritation parameter:
other: Draize Grades
Remarks:
Conjunctiva: redness, chemosis, discharge
Basis:
animal #3
Remarks:
ID Nr. 2374
Time point:
other: 1 h after application
Score:
ca. 2
Max. score:
2
Reversibility:
fully reversible within: 72 h
Remarks on result:
no indication of irritation
Irritation parameter:
other: Draize Grades
Remarks:
Conjunctiva: redness, chemosis, discharge
Basis:
animal #1
Remarks:
ID Nr. 2303
Time point:
24/48/72 h
Score:
ca. 2
Max. score:
2
Reversibility:
fully reversible within: 48 h
Remarks on result:
no indication of irritation
Irritation parameter:
other: Draize Grades
Remarks:
Conjunctiva: redness, chemosis, discharge
Basis:
animal #2
Remarks:
ID Nr. 2313
Time point:
24/48/72 h
Score:
ca. 1
Max. score:
2
Reversibility:
fully reversible within: 7 days
Remarks on result:
no indication of irritation
Irritation parameter:
other: Draize Grades
Remarks:
Conjunctiva: redness, chemosis, discharge
Basis:
animal #3
Remarks:
ID Nr. 2374
Time point:
24/48/72 h
Score:
ca. 1
Max. score:
2
Reversibility:
fully reversible within: 72 h
Remarks on result:
no indication of irritation
Irritation parameter:
other: Draize Grades
Remarks:
Conjunctiva: redness, chemosis, discharge
Basis:
animal #2
Remarks:
ID 2313
Time point:
other: 4 days
Score:
ca. 1
Max. score:
2
Reversibility:
fully reversible within: 7 days
Remarks on result:
no indication of irritation
Irritation parameter:
other: Draize grades
Remarks:
Conjunctiva: redness, chemosis, discharge
Basis:
animal #2
Remarks:
ID Nr. 2313
Time point:
7 d
Score:
ca. 0
Max. score:
2
Reversibility:
fully reversible within: 7 days
Remarks on result:
no indication of irritation
Irritant / corrosive response data:
The conjuctiva reacted with diffuse redness (grade 2) in all 3 animals 1h after application. The findings had completely disappeared after 72 h to 7 days. Only at the day of application the conjuctivas were swollen (Grade 1). In addition, a slight discharge (grade 1) was observed in all 3 animals at the day of application. All effects were reversible after 48h, 72h or 7 days respectively.
It is considered that all effects were induced by the physical property (dust) of the test substance. Therefore the test substance was considered to be not irritant.

There were weakly irritating effects on the conjunctivae only: redness score 2 (of 4) in all animals after 1 h, score 2 and 1 after 24 h and reversible by 72 h. Chemosis and discharge was very slight only 1 h after application (score 1).

Interpretation of results:
GHS criteria not met
Conclusions:
No classification (EU and GHS)
Executive summary:

Jahn and Berthold (1991) studied eye irritation of precipitated silica in rabbits by the OECD 405 guideline test method. There were weakly irritating effects on the conjunctivae only: redness score 2 (of 4) in all animals after 1 h, score 2 and 1 after 24 h and reversible by 72 h. Chemosis and discharge were very slight only 1 h after application (score 1).

Endpoint:
eye irritation: in vivo
Type of information:
other: other: OECD evaluation of unpublished in vivo studies
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: A scientific review by authorative international body
Reason / purpose for cross-reference:
reference to same study
Principles of method if other than guideline:
OECD evaluated the available test data on synthetic amorphous silica.
GLP compliance:
no
Remarks:
review: both yes and no status
Species:
rabbit
Irritation parameter:
conjunctivae score
Basis:
mean
Time point:
other: 1 h
Score:
2
Max. score:
4
Reversibility:
fully reversible within: 72 hours
Remarks on result:
other: hydrophilic precipitated silica; redness 2 after 1h, and 2 and 1 after 24 h; very slight chemosis and discharge after 1h
Irritation parameter:
conjunctivae score
Basis:
mean
Time point:
other: no data
Score:
1
Max. score:
4
Reversibility:
fully reversible
Remarks on result:
other: hydrophilic precipitated silica
Irritant / corrosive response data:
The studies with synthetic amorphous silica did not cause eye irritation on rabbit.
Interpretation of results:
GHS criteria not met
Conclusions:
OECD (2004) includes six eye irritation studies with synthetic amorphous silica, of which two were regarded as critical studies for SIDS endpoint. These two studies were conducted with hydrophilic precipitated silica. None of the studies showed eye irritating effects on rabbit.
Executive summary:

In OECD (2004), all synthetic amorphous silica products tested as a powder (0.1 g) have shown no or only weak and transient irritating effects on the conjunctivae of the eyes of rabbits with the iris and cornea not affected at all. In conclusion, synthetic amorphous silica are not irritating to eyes under experimental conditions.

Endpoint:
eye irritation: in vivo
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
weight of evidence
Justification for type of information:
No toxicological data were available for silica fume and, therefore, a read-across approach was used. The dissolution, composition and surface properties were the most important parameters considered when deciding which substances can be used for read-across.

Based on the composition, surface characteristics, and bioaccessibility data, silica fume was assumed to have toxicological properties similar to those of sparingly synthetic amorphous silicas. Therefore read-across was carried out using available toxicological studies with synthetic amorphous silica (SAS).

Details on the read-across approach are presented in Iuclid section 13.
Reason / purpose for cross-reference:
read-across source
Reason / purpose for cross-reference:
read-across source
Remarks on result:
no indication of irritation
Interpretation of results:
GHS criteria not met
Conclusions:
The studies performed with silica and Na-Al-silicate do not indicate any eye irritation.
Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

There is data available on the irritant properties of synthetic amorphous silica. According to this data, synthetic amorphous silica and silicates are not irritating to the skin and eyes under experimental conditions. Based on the same amorphous structure and similar dissolution kinetics, silica fume is likely to resemble synthetic amorphous silica in this respect. No cases of skin or eye irritation have been reported in the literature from the ferrosilicon/silicon manufacturing industry or on the use of silica fume. Also, this supports the conclusion that silica fume can be considered to resemble synthetic amorphous silica in this respect. The dissolution of impurities from silica fume is generally low and comparable to that from synthetic amorphous silica. Therefore, they are not likely to hamper the read-across from synthetic amorphous silica in the assessment of irritancy.

Justification for classification or non-classification

Based on the weight-of-evidence and read-across from synthetic amorphous silica, silica fume is not a skin or eye irritant. No classification or further testing is proposed. Naturally, like any other dust, the dust from silica fume may also cause non-specific mechanical irritation to the eyes and respiratory tract.