Registration Dossier

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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Workers - Hazard via inhalation route

Systemic effects

Long term exposure
Hazard assessment conclusion:
no hazard identified
Acute/short term exposure
Hazard assessment conclusion:
no hazard identified
DNEL related information

Local effects

Long term exposure
Hazard assessment conclusion:
DNEL (Derived No Effect Level)
Value:
2 mg/m³
Most sensitive endpoint:
irritation (respiratory tract)
DNEL related information
DNEL derivation method:
ECHA REACH Guidance
Overall assessment factor (AF):
1
Dose descriptor:
NOAEC
Acute/short term exposure
Hazard assessment conclusion:
DNEL (Derived No Effect Level)
Value:
2 mg/m³
Most sensitive endpoint:
irritation (respiratory tract)
DNEL related information
DNEL derivation method:
ECHA REACH Guidance

Workers - Hazard via dermal route

Systemic effects

Long term exposure
Hazard assessment conclusion:
no hazard identified
Acute/short term exposure
Hazard assessment conclusion:
no hazard identified
DNEL related information

Local effects

Long term exposure
Hazard assessment conclusion:
hazard unknown (no further information necessary)
Acute/short term exposure
Hazard assessment conclusion:
medium hazard (no threshold derived)
Most sensitive endpoint:
skin irritation/corrosion
DNEL related information
DNEL derivation method:
other: It has a pH of >13

Workers - Hazard for the eyes

Local effects

Hazard assessment conclusion:
high hazard (no threshold derived)

Additional information - workers

This substance is a multi-constituent substance consisting of sodium hydroxide (215-185-5, 1310-73-2) and disodium metasilicate (229-912-9, 6834-92-0). It is the by-product of a reaction between zircon (EC no 239-019-6) and sodium hydroxide; after hydrolysis, this substance is the water-soluble fraction.  The substance has a pH of >13, due to the presence of significant amounts of sodium hydroxide. The substance as produced would be highly damaging to eyes due to the alkali content; testing would not be required to demonstrate this is the properties of sodium hydroxide are well-known. In vivo testing of the substance would be inappropriate on animal welfare grounds, and such testing for substances where the pH is >11 is prohibited. The substance is classified based on this as skin corrosion/irritation, category 1A (H314), i.e. corrosive. Disodium metasilicate (229-912-9) has been tested for eye irritancy; this would not contribute at all to the corrosiveness due to the sodium hydroxide present in this substance.

General Population - Hazard via inhalation route

Systemic effects

Long term exposure
Hazard assessment conclusion:
no hazard identified
Acute/short term exposure
Hazard assessment conclusion:
no hazard identified
DNEL related information

Local effects

Long term exposure
Hazard assessment conclusion:
hazard unknown (no further information necessary)
Acute/short term exposure
Hazard assessment conclusion:
medium hazard (no threshold derived)
Most sensitive endpoint:
skin irritation/corrosion
DNEL related information
DNEL derivation method:
other: It has a pH of >13

General Population - Hazard via dermal route

Systemic effects

Long term exposure
Hazard assessment conclusion:
no hazard identified
Acute/short term exposure
Hazard assessment conclusion:
no hazard identified
DNEL related information

Local effects

Long term exposure
Hazard assessment conclusion:
hazard unknown (no further information necessary)
Acute/short term exposure
Hazard assessment conclusion:
medium hazard (no threshold derived)
Most sensitive endpoint:
skin irritation/corrosion
DNEL related information
DNEL derivation method:
other: It has a pH of >13

General Population - Hazard via oral route

Systemic effects

Long term exposure
Hazard assessment conclusion:
hazard unknown (no further information necessary)
Acute/short term exposure
Hazard assessment conclusion:
medium hazard (no threshold derived)
Most sensitive endpoint:
skin irritation/corrosion
DNEL related information
DNEL derivation method:
other: It has a pH of >13

General Population - Hazard for the eyes

Local effects

Hazard assessment conclusion:
high hazard (no threshold derived)

Additional information - General Population

This substance is a multi-constituent substance consisting of sodium hydroxide (215-185-5, 1310-73-2) and disodium metasilicate (229-912-9, 6834-92-0). It is the by-product of a reaction between zircon (EC no 239-019-6) and sodium hydroxide; after hydrolysis, this substance is the water-soluble fraction.  The substance has a pH of >13, due to the presence of significant amounts of sodium hydroxide. The substance as produced would be highly damaging to eyes due to the residual alkali; testing would not be required to demonstrate this is the properties of sodium hydroxide are well-known. In vivo testing of the substance would be inappropriate on animal welfare grounds, and such testing for substances where the pH is >11 is prohibited. The substance is classified based on this as skin corrosion/irritation, category 1A (H314), i.e. corrosive. Disodium metasilicate (229-912-9) has been tested for eye irritancy; this would not contribute at all to the corrosiveness due to the sodium hydroxide present in this substance.

NaOH is not expected to be systemically available in the body under normal handling and use conditions and therefore acute systemic effects of NaOH after acute dermal or inhalation exposure are not expected to occur