Is Lactic Acid safe in cosmetics?
Lactic Acid has a safety rating of "GOOD" in our database. EU status: restricted. US status: permitted.
Lactic Acid
Also known as: DL-Lactic Acid, Propanoic acid, 2-hydroxy-, BRN 5238667, EINECS 200-018-0, EINECS 209-954-4 (+15 more)
INCI: LACTIC ACID
Lactic Acid (CAS 50-21-5) is a cosmetic active ingredient functioning as AHA exfoliant (MW 90 Da) with humectant properties. Slightly larger than. NOAEL 295.333333 mg/kg bw/day (cross-referenced against ToxValDB ECHA IUCLID); EU Regulation 1223/2009 status: restricted, max ≤2.5% at pH ≥5.0 for consumer leave-on products. Industrial safety data is also available in the chemical safety database. Same-CAS public records also appear in industrial chemical safety and pharmaceutical data.
View industrial chemical safety profile for CAS 50-21-5 →
Auto-generated CPSR Part A draft with source citations
Cross-Vertical Regulatory Divergence
Lactic Acid is classified GHS Danger (H314, H315, H318) in the chemicals database but is restricted in EU cosmetics at max ≤2.5% at pH ≥5.0 for consumer leave-on products.
Source: Cosmetics: ingredients.eu_status/eu_max; Chemicals: ghs_classifications.signal_word/hazard_statement_code
Function
AHA exfoliant (MW 90 Da) with humectant properties. Slightly larger than glycolic acid producing gentler exfoliation. Disrupts corneocyte cohesion and stimulates ceramide biosynthesis (L-isomer). At lower concentrations acts as a skin-identical humectant and Natural Moisturising Factor (NMF) component. Component of Jessner's solution used as a superficial-to-medium peel primer.
Safety Rating
GOOD
Regulatory Status
EU EU Status
restricted
EU Max Conc.
≤2.5% at pH ≥5.0 for consumer leave-on products
US US Status
permitted
US Notes
CIR reviewed: safe at ≤10% at pH ≥3.5 (consumer); ≤30% at pH ≥3.0 (professional). FDA references CIR guidance. Photosensitivity advisory applies. Optimal pH range 3.5–5.0 depending on target application. L-isomer clinically preferred for ceramide and barrier benefits.
For full compliance data across multiple jurisdictions, use the Substance Compliance tool.
Safety Data
Margin of Safety, dermal absorption, and sensitization profile summaries for Lactic Acid.
Calculate MoS for your specific formulation with the MoS Calculator.
GHS Hazard Classification
Globally Harmonized System classification per ECHA C&L inventory and ILO/WHO International Chemical Safety Cards.
Short-term Exposure Effects
The substance is corrosive to the eyes. The substance is irritating to the skin and respiratory tract. Corrosive on ingestion.
Routes of Exposure
The substance can be absorbed into the body by inhalation of its aerosol and by ingestion.
Pre-Calculated Safety Assessment
Pre-calculated NOAEL → SED → MoS audit trail for Lactic Acid across SCCS product categories, with measured dermal absorption where available.
Dermal Penetration Profile
Skin absorption and penetration characteristics of Lactic Acid, relevant to systemic exposure and MoS calculations.
Absorption %
12-20%
Penetration Level
epidermis
Penetration Depth
epidermis
Molecular Weight
90.1 Da
Log P
-0.72
Systemic Absorption
minimal
Topical Bioavailability
8-15%
Safety Margin Factor
moderate
Vehicle Dependent
Yes — absorption varies by formulation
Source: CIR 2014
EPA ToxValDB — Toxicity Values
10 toxicity values from EPA ToxValDB (aggregated from CCTE, HPV, ToxRefDB, IRIS, and other regulatory dossiers).
| Endpoint | Value | Species | Route | Duration | Source |
|---|---|---|---|---|---|
| LEL | =30000 mg/kg-day | Chicken | oral | subchronic | EFSA |
| LD50 | >2000 mg/kg | Rabbit | dermal | acute | ECHA IUCLID |
| LOEL | =57.6 mg/L | Mouse | oral | short-term | ECOTOX |
| NOEL | =57.6 mg/L | Mouse | oral | short-term | ECOTOX |
| LC50 | >7.94 mg/L | Rat | Inhalation | - | HPVIS |
| LD50 | >=3543 mg/kg | Rat | oral | - | HPVIS |
| LD50 | <=4936 mg/kg | Rat | oral | - | HPVIS |
| LD50 | >2000 mg/kg | Rabbit | dermal | - | HPVIS |
| LD50 | =1810 mg/kg | Guinea Pig | oral | - | ChemIDplus |
| LD50 | =4875 mg/kg | Mouse | oral | - | ChemIDplus |
Sensitization AOP Dashboard
Adverse Outcome Pathway data across 5 assays (DPRA, KeratinoSens, hCLAT, LLNA, NESIL) aggregated from public sources.
DPRA Cys %
0.55%
DPRA Lys %
0.05%
KeratinoSens IC50
2000 µM
hCLAT CV75
2400 µg/mL
LLNA EC3
25%
NESIL
6250 µg/cm²
LLNA: Weak (1B)
GHS: 1B
Source: LLNA: Gerberick et al. (2005); DPRA: Urbisch et al. 2015 [DOI:10.1016/j.yrtph.2014.12.008] | ECVAM Validation Study Report; KS: Bauch et al. 2011 [DOI:10.1016/j.tiv.2011.05.030] | Emter et al. 2010 [DOI:10.1016/j.taap.2010.03.009]; hCLAT: Urbisch et al. 2015 [DOI:10.1016/j.yrtph.2014.12.008] | Bauch et al. 2011 [DOI:10.1016/j.tiv.2011.05.030]
ECHA REACH Registration
European Chemicals Agency REACH dossier and Substances of Very High Concern listing.
Registration Type
Full
Tonnage Band
100 - 1,000 tonnes
Substance Type
SUBSTANCE; GROUP
SVHC Candidate
No
Expanded Jurisdictional Detail
Additional regulatory detail beyond the 7-jurisdiction summary: Saudi SFDA, Korea MFDS, ASEAN ACD, Japan/Korea, Brazil/India, and cross-jurisdictional restriction entries.
Additional Jurisdictional Restrictions (2)
| Jurisdiction | Status | Max % | Product Type |
|---|---|---|---|
| CN | restricted | 6 | (a) Rinse-off (b) Leave-on skin products |
| AE | restricted | 10.0 | Leave-on products |
Typical Use Concentrations
Reported concentration ranges per product category from SCCS/CIR/industry sources.
| Product Category | Typical Range | Max Reported | Source |
|---|---|---|---|
| Toner/Exfoliant | 2–10 | 20 | CIR |
| Face Cream | 0.5–5 | 10 | CIR |
Additional Ingredient Properties
10 property records from structured ingredient metadata.
acne
{"cas_number": "50-21-5", "anti_acne_mechanism": "keratolytic/comedolytic", "comedogenicity_rating_0_to_5": "0", "acne_type_efficacy": "non_inflammatory", "p_acnes_mic_ug_per_ml": "No direct antibacterial", "sebum_reduction_pct_clinical": "5-8", "keratolytic_strength": "mild-moderate", "exfoliation_mechanism": "chemical", "optimal_ph_for_efficacy": "3.5-4.0", "aha_type": "lactic", "peel_depth": "s…
anti_aging
{"anti_aging_claim": "hydration-plumping, brightening, anti-wrinkle, barrier-repair", "mechanism_of_action": "Exfoliation, increases ceramide synthesis, NMF component, tyrosinase inhibition", "target_skin_layer": "stratum corneum, epidermis", "collagen_stimulation": "Mild-Moderate", "elastin_protection": "Mild", "wrinkle_reduction_pct": "10-20", "clinical_study_duration_weeks": "12", "sample_size"…
anti_pollution
{"cas_number": "50-21-5", "ingredient_class": "other", "primary_mechanism": "barrier_reinforcement", "pollution_types_targeted": "PM2_5", "IR_A_protection": "no", "visible_light_protection": "no", "digital_screen_protection_claim": "no", "PAH_neutralization": "no", "ozone_protection": "no", "mitochondrial_protection": "no", "Nrf2_activation": "no", "AhR_pathway_modulation": "no", "NF_kB_inhibition…
baby_pediatric
{"cas_number": "50-21-5/598-82-3", "ingredient_class": "other", "pediatric_safety_rating": "caution", "minimum_age_months": "12", "neonatal_safe": "no", "premature_infant_safe": "insufficient_data", "skin_barrier_maturity_consideration": "AHA, exfoliant; generally avoid <12yr; very low pH concern", "transepidermal_absorption_risk_pediatric": "moderate", "systemic_exposure_concern_pediatric": "low"…
comedogenicity_detail
{"comedogenicity_rating": "0", "irritancy_rating": "2", "skin_type_suitability": "all,dry,combination,normal,mature", "acne_safe": "yes", "source": "AHA exfoliant"}
concentration
{"min_concentration_pct": "5.0", "max_concentration_pct": "12.0", "typical_concentration_pct": "10.0", "product_type": "Moisturizer", "function_at_concentration": "Exfoliation, hydration", "source": "CIR Safety Assessment"}
deodorant
{"cas_number": "50-21-5", "ingredient_class": "astringent", "mechanism_of_action": "pH_modification", "antiperspirant_efficacy_sweat_reduction_pct": "0", "deodorant_efficacy_hours": "4-8", "odor_reduction_pct": "25-45", "bacteriostatic": "yes", "bactericidal": "limited", "microbiome_impact": "neutral", "axillary_microbiome_effect": "varies by ingredient", "MIC_value_if_antimicrobial": "varies", "a…
depigmentation
{"cas_number": "50-21-5", "ingredient_class": "keratinocyte_turnover_enhancer", "primary_mechanism_of_action": "AHA with humectant properties; gentler exfoliation for brightening", "secondary_mechanisms": "Variable", "molecular_target": "other", "tyrosinase_inhibition_IC50_uM": "varies", "tyrosinase_inhibition_type": "competitive", "melanin_reduction_pct_in_vitro": "25-45", "melanin_reduction_pct_…
Function Categories & List Membership
Cosmetic/Chemical Function Categories
Abrasive
Antioxidant
Biocide
Chelating agent
Cleaning agent
Degradant/impurity
Flavouring and nutrient
Food preservative
Fragrance
Humectant
Regulatory List Membership (6)
EU Regulated in Personal Care
EU Restricted for Children (Cosmetics)
IFRA Fragrance Transparency List
EPA Safer Chemical Ingredients List (SCIL)
FDA Substances Added to Food (EAFUS)
Consumer Product Chemical
Expert Verdict
Expert safety assessment and concern-level summary for Lactic Acid.
Regulatory Flags
photosensitizing
ph-critical
l-isomer-preferred
humectant-dual-function
eu-restricted
nmf-component
jessners-component
eu_children_restricted
epa_safer_alternative
ifra_fragrance
fda_food_additive
Known Synonyms
DL-Lactic Acid
Propanoic acid, 2-hydroxy-
BRN 5238667
EINECS 200-018-0
EINECS 209-954-4
Ethylidenelactic acid
FEMA No. 2611
FEMA Number 2611
1-Hydroxyethanecarboxylic acid
alpha-Hydroxypropionic acid
Lactate
Lactic acid USP
Lactovagan
Ordinary lactic acid
Propionic acid, 2-hydroxy-
Racemic lactic acid
EPA Pesticide Chemical Code 128929
Acidum lacticum
Aethylidenmilchsaeure
(RS)-2-Hydroxypropionsaeure
Chemical Function
pH regulating agent
Humectant
Softener and conditioner
Biocide
Regulatory Lists
active_ingredient; Europe; Pesticides
SCIL (9/2019)
Canada; consumer_product; Substances in Products - Canada (4/2014)
drinking_water; Europe; manufacturing; plastic_additive
active_ingredient; Pesticides
active_ingredient; Pesticides
active_ingredient; Pesticides
active_ingredient; Pesticides
active_ingredient; Pesticides
active_ingredient; Pesticides
active_ingredient; Pesticides
active_ingredient; Europe; Pesticides
active_ingredient; Australia
inert_ingredient; Pesticides
inert_ingredient; non_food_use; Pesticides
pharmaceutical
active_ingredient; Europe; Pesticides
active_ingredient; Pesticides
Cross-Vertical Safety Context
Same-CAS public records found in pharmaceutical data.
SOURCE
ChEMBL / DrugCentral / FAERS
DB_PHARMA CAS match
Pharmaceutical Data
Same-CAS rows from the pharmaceutical spoke database.
Compound
LACTIC ACID
ChEMBL ID
CHEMBL1200559
Max Phase
4
Adverse Event Associations
3
Frequently Asked Questions
Is Lactic Acid allowed in the EU?
Lactic Acid EU regulatory status: restricted. Maximum allowed concentration: ≤2.5% at pH ≥5.0 for consumer leave-on products. This is based on EU Regulation 1223/2009 and its amendments.
What does Lactic Acid do in cosmetics?
Lactic Acid functions as: AHA exfoliant (MW 90 Da) with humectant properties. Slightly larger than glycolic acid producing gentler exfoliation. Disrupts corneocyte cohesion and stimulates ceramide biosynthesis (L-isomer). At lower concentrations acts as a skin-identical humectant and Natural Moisturising Factor (NMF) component. Component of Jessner's solution used as a superficial-to-medium peel primer.. It is classified as a Active Ingredient in our database. CAS number: 50-21-5.
Is Lactic Acid used outside cosmetics?
Lactic Acid also appears in industrial chemical safety and pharmaceutical data. The cross-vertical cards on this page render same-CAS public rows from the matched databases.
Does Lactic Acid have different safety status in cosmetics vs industrial chemicals?
Lactic Acid is classified GHS Danger (H314, H315, H318) in the chemicals database but is restricted in EU cosmetics at max ≤2.5% at pH ≥5.0 for consumer leave-on products.
Compliance Tools
Check Lactic Acid compliance across multiple jurisdictions:
Ingredient Decoder
Paste a full ingredient list for instant analysis
82 Allergen Checker
Check for EU declarable fragrance allergens
Substance Compliance
Check compliance across multiple jurisdictions
MoS Calculator
Calculate Margin of Safety using SCCS methodology
Heavy Metal Limits
Compare limits across jurisdictions
Related Ingredients
Acetyl Tetrapeptide-5
Excellent
Same category
Anti-edema peptide for periorbital ar...
Activated Charcoal
Excellent
Same category
Adsorbent; skin cleanser; pore-cleans...
Adenosine
Excellent
Same category
Skin-conditioning agent, anti-aging, ...
Allantoin
Excellent
Same category
Skin conditioner, keratolytic, anti-i...
Alpha-Glucan Oligosaccharide
Excellent
Same category
prebiotic, skin-conditioning
Ascophyllum Nodosum Extract
Excellent
Same category
Skin Brightening, Tyrosinase Inhibito...
(AGARICUS BLAZEI FERMENT + GANODERMA LUCIDUM FERMENT + GANODERMA MULTIPILEUM FERMENT) EXTRACT
Good
Similar safety
Anti-sebum, Antioxidant, Skin Protecting
(ANGELICA ACUTILOBA/PAEONIA LACTIFLORA/REHMANNIA GLUTINOSA) ROOT/CNIDIUM OFFICINALE RHIZOME EXTRACT
Good
Similar safety
Skin Conditioning, Skin Conditioning ...
(ANGELICA ACUTILOBA/PAEONIA LACTIFLORA/REHMANNIA GLUTINOSA/SCUTELLARIA BAICALENSIS) ROOT/(CNIDIUM OFFICINALE/COPTIS CHINENSIS) RHIZOME/GARDENIA JASMINOIDES FRUIT/PHELLODENDRON CHINENSE BARK EXTRACT
Good
Similar safety
(ANGELICA GIGAS/GLYCYRRHIZA URALENSIS/REHMANNIA GLUTINOSA ROOT)/ANGELICA GIGAS STEM/CARTHAMUS TINCTORIUS FLOWER/(CARTHAMUS TINCTORIUS/PRUNUS PERSICA SEED)PORIA COCOS WATER
Good
Similar safety
Humectant, Skin Conditioning, Skin Pr...
(ANGELICA KEISKEI/CHRYSANTHEMUM ZAWADSKII) LEAF/STEM/CINNAMOMUM CASSIA BARK/TRICHOSANTES KIRILOWII FRUIT/ULMUS DAVIDIANA BARK/ROOT/(PAEONIA JAPONICA/BUPLEURUM FALCATUM/POLYGALA TENUIFOLIA ROOT)/VISCUS ALBUM STEM EXTRACT
Good
Similar safety
Anti-seborrheic, Anti-sebum, Antioxid...
(APPLE/CITRUS JUNOS/LENTIL/PEAR/PUMPKIN/STRAWBERRY/TOMATO FRUIT)/CORN KERNEL/(ARCTIUM LAPPA/BRASSICA OLERACEA ACEPHALA/CABBAGE/CAMELLIA SINENSIS/MORINGA OLEIFERA/RADISH/SPINACH LEAF)/(SORGHUM BICOLOR LEAF/STEM)/OAT MEAL/POTATO PULP/(CARROT/NELUMBO NUCIFERA/RADISH/WILD YAM ROOT)/(AMARANTHUS HYPOCHONDRIACUS/CASHEW/CICER ARIETINUM/COIX LACRYMA-JOBI MA-YUEN /MACADAMIA TERNIFOLIA/PHASEOLUS ANGULARIS/PISTACIA VERA/RHYNCHOSIA NULUBILIS/RICE/SESAME/SETARIA ITALICA/SOYBEAN/SWEET ALMOND/WHEAT SEED)/HORDEUM VULGARE SPROUT/CYPERUS ESCULENTUS TUBER/ARTEMISIA PRINCEPS/BROCCOLI/CHENOPODIUM QUINOA/ENTEROMORPHA COMPRESSA/HORDEUM VULGARE/IPOMOEA BATATAS/LAMINARIA JAPONICA/LENTINUS EDODES/PLEUROTUS OSTREATUS/PORPHYRA TENERA/UNDARIA PINNATIFIDA EXTRACT
Good
Similar safety
Antioxidant
Ascorbic Acid
Excellent
Chemical family
Antioxidant; ROS scavenger; vitamin E...
Ascorbic Acid (Vitamin C)
Excellent
Chemical family
Antioxidant, skin brightening
Ergocalciferol
Moderate
Chemical family
Skin Conditioning
Is Lactic Acid in Your Products?
Scan any product label with Piro — our free ingredient scanner. Point your camera at the ingredients list and get instant safety scores for every ingredient.
Try Piro Free →Analyze Your Full Ingredient List
Paste any INCI list into the Decoder for instant safety analysis, or calculate the Margin of Safety for Lactic Acid in your formulation.