What does Magnesium oxide do?

Used in cosmetics as an absorbent, a pH buffer and an opacifier.

Is Magnesium oxide safe?

Moderate concern: no hazard classifications on record. It is listed for cosmetic use in the EU.

beauty
cleaning
food
industrial

Magnesium oxide

CAS 13589-16-7 · 40/100 · High conf.

Also registered as 8 other CAS numbers

52933-73-0 · 82375-77-7 · 185461-91-0 · 187036-80-2 · 227961-49-1 · 1193320-89-6 · 2408628-73-7 · 1309-48-4

Concern score

40/100Moderate concern based on regulatory listings.

High confidence

Magnesium oxide in plain language

What it is: Also known as Light magnesium oxide · Heavy magnesium oxide · Magnesia · Magnesium oxide heavy · Magnesium monoxide · magnesium oxygen(2-)
Show all 28 names
1309484 BG Magox (25KG/BG) · Axzkoiwuvfpnlo-uhfffaoysa-n · Akro-Mag Bars Green · Akro-Mag Green · Anscor P · Calcined magnesia · Causmag · E-530 · Ins NO.530 · INS-530 · Magnesium oxide (CI 77711) · Magnesium oxide (MgO) · Magnesium oxide 30-50nm · Magnesium oxide 325 mesh · Magnesium oxide, · MgO · magnesium (II) oxide · magnesium oxide (periclase) · magnesiumoxide · Magnesia oxydata · Magnesium (as oxide) · Clenpiq component magnesium oxide
What it does: Used in cosmetics as an absorbent, a pH buffer and an opacifier.
Absorbent
Buffering
Opacifying
Anticaking agent
pH adjuster
Opacifier
Is it a concern?: Moderate concern: no hazard classifications on record. It is listed for cosmetic use in the EU.

Why it's flagged

EPA CPDat observed this chemical in 1856 composition records across product categories including Construction and building materials, Furniture and furnishings, Raw materials.

The score describes this ingredient's chemical identity — its hazard profile from published classifications and regulatory status — not the safety of any product it appears in.

Regulation

No restrictions found. Magnesium oxide appears in these published regulatory listings.

In marketed US drugs
Inactive ingredient in US drugs

Recorded in these product areas

Found in consumer products
Beauty
Cleaning
Industrial

USFDAinactive ingredient database9 entries — 3 administration routes
- Route: ORAL; Dosage form: CAPSULE; Maximum daily exposure: 20 mgSource →
- Route: ORAL; Dosage form: CAPSULE, DELAYED RELEASE; Maximum daily exposure: 78 mgSource →
- Route: ORAL; Dosage form: CAPSULE, EXTENDED RELEASE; Maximum daily exposure: 75 mgSource →
- Route: ORAL; Dosage form: TABLET; Maximum daily exposure: 63 mgSource →
- Route: ORAL; Dosage form: TABLET, DELAYED RELEASE; Maximum daily exposure: 368 mgSource →
- Route: BUCCAL; Dosage form: GUM, CHEWING; Maximum daily exposure: 173 mgSource →
- Route: ORAL; Dosage form: TABLET, FILM COATED; Maximum daily exposure: 80 mgSource →
- Route: SUBLINGUAL; Dosage form: TABLET; Maximum daily exposure: 15 mgSource →
- Route: ORAL; Dosage form: TABLET, EXTENDED RELEASE; Potency: 25.74 mgSource →
EUCosIngActiveListed in CosIng inventory for cosmetic use.
- Listed in CosIng inventory for cosmetic use.Source →
GLOBALJECFANOT LIMITEDJECFA evaluation lists ADI NOT LIMITED. Functional class: anticaking agent.
- JECFA evaluation lists ADI NOT LIMITED. Functional class: anticaking agent.Source →
USEPAcommercial use observedEPA CPDat observed this chemical in 1856 composition records across product categories including Construction and building materials, Furniture and furnishings, Raw materials. EPA CPDat classifies this chemical for functional uses including Absorbent, pH regulating agent, Opacifer.
- EPA CPDat observed this chemical in 1856 composition records across product categories including Construction and building materials, Furniture and furnishings, Raw materials. EPA CPDat classifies this chemical for functional uses including Absorbent, pH regulating agent, Opacifer.Source →
USFDAmarketed drug occurrenceFDA NDC lists this ingredient in 80 active drug products and 83 total products.
- FDA NDC lists this ingredient in 80 active drug products and 83 total products.Source →
USFDAlisted in openFDA substanceopenFDA substance registry classifies this ingredient as chemical.
- openFDA substance registry classifies this ingredient as chemical.Source →

Expert safety opinions

Independent scientific assessments cited by the records we hold, with the year and link where the record gives one.

SCCS
EU Scientific Committee on Consumer Safety
No SCCS opinion on file.
CIR
Cosmetic Ingredient Review (US expert panel)
No CIR safety assessment on file.
JECFA
Joint FAO/WHO Expert Committee on Food Additives
- JECFA evaluation lists ADI NOT LIMITED. Functional class: anticaking agent.
  Year not recorded · GLOBAL JECFA listing · Read the source →

Evidence & sources

No graded research studies for Magnesium oxide yet. This record is compiled from the published data sources below — registries and regulatory listings, not study findings.

9 data sources

Where this comes from

CosIng
regulatory · updated 2026-09-23
Open →
EPA Chemical and Products Database
exposure · updated may 11, 2016
Open →
EPA DSSTox Identifiers
chemistry · updated 2025-12-29
Open →
FDA Inactive Ingredient Database
regulatory · updated 2026-01-09
Open →
FDA National Drug Code Directory
regulatory · updated 2030-07-31
Open →
FDA GSRS UNII
registry · updated 2026-02-26
Open →
WHO JECFA Database
regulatory · updated 2026-10-04
Open →
openFDA Substance
registry · updated 2026-05-24
Open →
PubChem Live Enrichment
chemistry · updated 2026-05-17
Open →

Reference links (1)

Openfda substance

codexalimentarius.net

Read →

Suitability

Context-specific fit derived from published classifications and the current ingredient evidence profile.

Food use

Food-use source coverage is present in the current record.

Good fit

The ingredient appears in food-oriented source coverage or allowed-use references, which makes food use easier to support than a context with no domain signal at all.

Fragrance avoidance

No fragrance-linked caution surfaced in the current profile.

Good fit

This ingredient does not currently read as a fragrance-linked driver in the published evidence and hazard profile.

Where it has been recorded

How often EPA CPDat has listed Magnesium oxide in a product composition. These are source records, not Greenveil catalog products.

Source records

1,856

Named organisations

Construction and building materialsFurniture and furnishingsRaw materialsOther direct contact consumer goodsCleaning and safetyLaboratory supplies

Typical roles

AbsorbentBufferingOpacifyingAnticaking agentpH adjusterOpacifier

See products using Magnesium oxide →

Catalog

Found in these products

Cosmetic and personal-care products that list Magnesium oxide are shown first. Their ingredient lists include Magnesium oxide; each product's own rating depends on its whole formula, so it is shown on the product page, not here.

See all 24 →Find products without it →