Sodium hydroxide COSHH data sheet: hazards, exposure limit and SDS summary

A strong alkali that causes severe burns to skin and eyes on contact. Found in oven cleaners and drain cleaners as a solid, gel or solution.

Hazard data from the HSE GB MCL, the ECHA C&L Inventory and HSE EH40, checked 8 September 2026. Classification checked automatically against the HSE GB mandatory classification list (version 8) and the ECHA C&L inventory on 9 September 2026. Confirm the concentration and form against the supplier data sheet for the product you use.

Identification

CAS number	1310-73-2
EC number	215-185-5
Physical form	liquid
Signal word	DANGER
Pictograms	GHS05 Corrosive
Routes of exposure	skin, eyes, inhalation, ingestion

Hazard classification

Harmonised classification from the GB mandatory classification list (index 011-002-00-6), with supplier self-classifications marked. Skin Corr 1A applies at 5% and above. Solutions of 2 to 5% are Skin Corr 1B, and 0.5 to 2% are skin and eye irritants. About half of suppliers add H290 (corrosive to metals).

Skin corrosion, category 1A
Corrosive to metals, category 1 (supplier classification)

Hazard statements

H290 May be corrosive to metals. (supplier classification)
H314 Causes severe skin burns and eye damage.

Workplace exposure limit

Reference period	ppm	mg/m³
Short term (15 minute)	—	2

Products that contain it

Common products whose hazard data comes from this record. The concentration and form vary, so always check the product data sheet.

Cif Pro Formula Oven & Grill Cleaner (Cif (Diversey)). Caustic spray. Corrosive to skin and eyes.
Mr Muscle Oven Cleaner (Mr Muscle (SC Johnson)). Caustic aerosol. Spraying makes inhalation more likely; ventilate.
Oven Pride (Oven Pride). Caustic solution used in a bag. Gloves supplied; goggles still needed.
Dri-Pak Caustic Soda (Dri-Pak). Solid sodium hydroxide. Reacts with water and gives off heat; add to water, never water to it.

Common uses

Oven and grill cleaning
Drain unblocking
Degreasing

First aid

Skin: rinse immediately with plenty of water for at least 15 minutes and get medical attention. Eyes: rinse for at least 15 minutes and go to A&E. Swallowed: rinse mouth, do not induce vomiting, call 999.

In an emergency call 999. For advice call NHS 111. Always follow section 4 of the safety data sheet for the product you have.

Storage

Closed, labelled container away from acids, aluminium and water. Locked away from public access.

Sources

HSE GB mandatory classification and labelling list (GB MCL), Index 011-002-00-6. Checked 8 September 2026.
ECHA C&L Inventory, CAS 1310-73-2, ECHA 100.013.805. Checked 8 September 2026.
HSE EH40/2005 Workplace exposure limits (2020 edition), Table 1. Checked 8 September 2026.

We do not host or copy manufacturer safety data sheets. Ask your supplier for the current sheet for the product you use.