Safety data reference
Citric Acid Monohydrate (Food Grade) — Safety Data Summary
- CAS5949-29-1
- EC611-842-9 (anhydrous: 201-069-1)
- FormulaC6H8O7·H2O
- MW210.14 g/mol (anhydrous 192.12 g/mol)
Read this before you use this page
This is a general reference summary for Citric Acid Monohydrate (Food Grade), compiled from publicly published authoritative sources — PubChem, the NIOSH Pocket Guide, ILO/WHO International Chemical Safety Cards, CAMEO Chemicals, the ECHA C&L Inventory, OSHA and the eCFR. Every figure on this page is traceable to one of the sources listed at the foot of the page.
It is not a supplier safety data sheet and must not be used as one. A compliant SDS is batch-specific and manufacturer-specific: it carries the actual supplier identity, emergency contact, product identifier, grade, impurity profile and the classification that follows from them. Before you accept, store, handle or ship any consignment, obtain the manufacturer’s own signed SDS for that grade and lot.
01Hazard identification
Classification: Skin irritation, Category 2 · Serious eye irritation, Category 2 · STOT single exposure, Category 3 (respiratory irritation). Self-classified — no harmonised CLP Annex VI entry exists
Pictograms: GHS07 Exclamation mark
- H319 Causes serious eye irritation.
- H315 Causes skin irritation.
- H335 May cause respiratory irritation.
Identification
| IUPAC name | 2-hydroxypropane-1,2,3-tricarboxylic acid hydrate |
|---|---|
| Synonyms | Citric acid hydrate, E 330, INS 330, acidum citricum monohydricum. Anhydrous form CAS 77-92-9 |
| CAS number | 5949-29-1 |
| EC number | 611-842-9 (anhydrous: 201-069-1) |
| Molecular formula | C6H8O7·H2O |
| Molecular weight | 210.14 g/mol (anhydrous 192.12 g/mol) |
02Precautionary statements
Prevention
- P261 Avoid breathing dust, fume, gas, mist, vapours or spray.
- P264 Wash hands thoroughly after handling.
- P271 Use only outdoors or in a well-ventilated area.
- P280 Wear protective gloves, protective clothing, eye protection and face protection.
Response
- P302+P352 IF ON SKIN: Wash with plenty of water.
- P304+P340 IF INHALED: Remove person to fresh air and keep comfortable for breathing.
- P305+P351+P338 IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses if present and easy to do. Continue rinsing.
- P332+P317 If skin irritation occurs: Get medical help.
- P337+P317 If eye irritation persists: Get medical help.
- P362+P364 Take off contaminated clothing and wash it before reuse.
Storage
- P403+P233 Store in a well-ventilated place. Keep container tightly closed.
- P405 Store locked up.
Disposal
- P501 Dispose of contents and container to an approved waste disposal plant.
03Physical and chemical properties
| Appearance | Slightly deliquescent white or colourless crystals, granules or powder |
|---|---|
| Odour | Odourless. Taste strongly acidic and tart |
| pH | 2.2 for a 0.1 N aqueous solution |
| Melting point | 135 °C (monohydrate). Anhydrous 153 °C |
| Boiling point | Not applicable — decomposes above 175 °C |
| Flash point | 100 °C (ICSC 0855, anhydrous). CAMEO records data unavailable |
| Flammability | Combustible solid. Finely dispersed particles form explosive mixtures in air |
| Dust explosion range | 0.28–2.29 kg/m3 |
| Auto-ignition | 1010 °C (powder) |
| Vapour pressure | 1.66 × 10−8 mmHg at 25 °C (estimated); non-volatile |
| Relative density | 1.542 g/cm3 (monohydrate) |
| Water solubility | 59.2 g/100 mL at 20 °C, rising to 84 g/100 g at 100 °C |
| log Pow | −1.72 at 20 °C |
| pKa1 | 2.79 |
| Decomposition temp. | 175 °C |
04Exposure controls and occupational limits
| OSHA PEL | None established |
|---|---|
| NIOSH REL | None established |
| ACGIH TLV | None identified |
| NIOSH IDLH | None established |
| German MAK | 2 mg/m3 (inhalable fraction) |
05First-aid measures
- Inhalation
- Fresh air, rest. Seek medical attention if symptoms develop.
- Skin contact
- Remove contaminated clothing. Rinse skin with plenty of water or shower. Flood the affected skin with water immediately.
- Eye contact
- Rinse first with plenty of water for several minutes, removing contact lenses if easily possible, then refer for medical attention. Flush for 20–30 minutes.
- Ingestion
- Rinse mouth and give one or two glasses of water to drink. Do NOT induce vomiting. Contact poison control.
06Fire-fighting measures
- Suitable extinguishing media
- Water spray, foam, dry chemical powder, carbon dioxide.
- Unsuitable media
- No specific unsuitable media identified in the consulted authorities.
- Specific hazards
- Combustible. Finely dispersed particles form explosive mixtures in air, so a dust explosion is possible in powder or granular form. Melts and decomposes in fire, emitting acrid smoke and fumes.
- Protective equipment
- Dust mask, or positive-pressure self-contained breathing apparatus for fire conditions. Goggles or face shield and protective gloves.
07Accidental release measures
- Personal precautions
- Use a particulate filter respirator matched to the airborne concentration, with gloves and eye protection. Prevent dust dispersion.
- Environmental precautions
- No specific measure is required by the consulted authorities, since citric acid is readily biodegradable and of low aquatic toxicity. Avoid discharging large quantities or unneutralised acidic solution to watercourses.
- Containment and clean-up
- Sweep the spilled substance into covered containers, moistening first to prevent dusting where appropriate, and wash away the remainder with plenty of water. Pick up residue with water-dampened absorbent paper and wash contaminated surfaces with soap and water.
08Handling and storage
- Safe handling
- Prevent dispersion of dust. No open flames. Use closed systems, dust-explosion-proof electrical equipment and lighting. Prevent dust deposition. Provide local exhaust or breathing protection. Do not eat, drink or smoke during work, and wash hands after handling.
- Safe storage
- Dry, at ambient temperature, in tight containers to exclude moist air. Avoid high humidity and elevated temperature, which cause caking. Keep separated from incompatible materials.
- Incompatible materials
- Strong oxidants, strong bases, reducing agents and metal nitrates. Attacks copper, zinc, aluminium and their alloys.
09Stability and reactivity
- Reactivity
- Reacts with oxidising agents, bases, reducing agents and metal nitrates. The aqueous solution is a weak acid and attacks copper, zinc, aluminium and their alloys.
- Chemical stability
- Stable under normal ambient conditions in dry, tightly closed containers. The monohydrate loses its water of crystallisation at around 40–50 °C and becomes anhydrous by about 150 °C.
- Hazardous reactions
- Potentially explosive reaction with metal nitrates — a documented incident involved vacuum evaporation of an aqueous mixed-metal-nitrate and citric acid solution exploding near dryness. Dust and air mixtures are explosive.
- Conditions to avoid
- Heat above 175 °C, open flame, ignition sources, dust generation and accumulation, and moisture or high humidity.
- Decomposition products
- Acrid smoke and fumes; carbon monoxide and carbon dioxide on combustion.
10Toxicological information
| LD50 oral, rat | 3,000 mg/kg. Other studies report 5,000; 6,730; 11,700 and 12,000 mg/kg bw |
|---|---|
| LD50 oral, mouse | 5,040–5,400 mg/kg bw |
| LD50 dermal, rabbit | No data available — OECD SIDS records no studies located |
| LC50 inhalation, rat | No data available — OECD SIDS records no studies located |
| Skin irritation | Slightly irritating in rabbit (OECD 404). A 30% aqueous solution produced no effect on intact skin |
| Eye irritation | Irritating to severely irritating in rabbit (OECD 405). Prolonged irrigation with 0.5–2% solutions caused permanent corneal opacity |
| Sensitisation | Rare. Isolated human case reports only |
| Target organs | Eyes, skin, respiratory tract — local irritant effects. No specific systemic target organ identified |
| IARC | Not classified |
| NTP | Not listed in the Report on Carcinogens, 15th Edition |
| OSHA | Not regulated as a carcinogen |
| Supporting data | No evidence of carcinogenicity in rats fed up to 5% citric acid for two years |
11Ecological information
| LC50 fish | Lepomis macrochirus 96 h 1,516 mg/L; Leuciscus idus 96 h 440–760 mg/L (solution not neutralised) |
|---|---|
| EC50 Daphnia magna | 1,535 mg/L neutralised; 85 mg/L not neutralised. The difference is a pH artefact, not intrinsic toxicity |
| Algae | Scenedesmus quadricauda EC0 640 mg/L, 7 d |
| Biodegradability | Readily biodegradable — 97% CO2 evolution (Modified Sturm); 100% DOC removal in AFNOR, Sturm and OECD screening tests |
| Bioaccumulation | Low — estimated BCF 3 |
| Mobility in soil | Very high — estimated Koc approximately 10. Exists almost entirely as the anion at environmental pH |
12Transport information
| UN number | None assigned |
|---|---|
| DOT (49 CFR 172.101) | Not listed in the Hazardous Materials Table — not regulated as a hazardous material for US ground transport |
| Proper shipping name | Not applicable |
| Transport hazard class | None |
| Packing group | None |
| Marine pollutant | No |
| IATA / IMDG | Not classified as dangerous goods |
13Regulatory information
| TSCA | Listed on the TSCA Inventory; subject to Chemical Data Reporting |
|---|---|
| SARA 313 (TRI) | Not listed |
| California Prop 65 | Not listed |
| EU REACH | Registered. No harmonised CLP Annex VI classification |
| FDA GRAS | 21 CFR 184.1033 — affirmed as GRAS for use in food with no limitations other than current good manufacturing practice |
| EU food additive | E 330 under Regulation (EC) No 1333/2008; purity criteria in Regulation (EU) No 231/2012 |
| JECFA | INS 330; specification in the FAO/WHO Combined Compendium, Monograph 16 |
| Compendial standards | FCC “Citric Acid”; USP–NF “Citric Acid Monohydrate”; Ph. Eur. “Citric acid monohydrate” |
14Food grade versus technical grade
Food grade is defined by a compendial monograph. Technical grade is not defined by any public standard, so the practical difference is the presence or absence of these binding limits.
| Parameter | Food grade (FCC / USP–NF / E 330) | Technical grade |
|---|---|---|
| Assay | 99.5–100.5% on the anhydrous basis | No compendial assay window |
| Water content | 7.5–8.8% (monohydrate). Anhydrous grade not more than 0.5% | Not specified |
| Sulphated ash | Not more than 0.05% | Not specified |
| Lead | Not more than 0.5 mg/kg | Not specified |
| Oxalates | Not more than 100 mg/kg | Not specified — a fermentation-residue control |
| Readily carbonizable substances | Must not produce a colour darker than the specified standard | No equivalent test |
| Manufacture | cGMP per 21 CFR 184.1033(c); route constrained to citrus juice recovery or fermentation with approved organisms | No process obligation |
Frequently asked questions
Is citric acid a dangerous good for shipping?
No. Citric acid has no UN number and does not appear anywhere in 49 CFR, so it is not regulated as a hazardous material for ground, air or sea transport. It still needs sound packaging against moisture, because the monohydrate cakes badly in humid conditions.
What is the difference between food grade and technical grade citric acid?
Food grade is defined by a compendial monograph — FCC, USP–NF, Ph. Eur. or E 330 — which binds assay to 99.5–100.5%, water content to 7.5–8.8% for the monohydrate, sulphated ash to 0.05%, lead to 0.5 mg/kg and oxalates to 100 mg/kg, and requires cGMP manufacture. Technical grade has no public standard at all, so none of those limits are guaranteed.
What is the difference between citric acid monohydrate and anhydrous?
Water content, and therefore effective acid strength per kilogram. The monohydrate carries 7.5–8.8% water of crystallisation and melts at 135 °C; the anhydrous form holds not more than 0.5% water and melts at 153 °C. Monohydrate is standard for beverages and general food use; anhydrous is preferred in dry blends and effervescent formulations where moisture would trigger premature reaction.
Can citric acid dust explode?
Yes. Citric acid is a combustible solid and finely dispersed particles form explosive mixtures in air within roughly 0.28–2.29 kg/m³. Powder handling needs closed systems, dust-explosion-proof electrical equipment and control of dust deposition, exactly as for any organic powder.
Is citric acid safe to handle without PPE?
It is far less hazardous than a mineral acid, but it is not inert. Rabbit studies show it is irritating to severely irritating to the eye, and prolonged contact with dilute solution has caused permanent corneal opacity. Goggles and gloves are appropriate, along with dust control, since it may cause respiratory irritation.
Supply
We supply Citric Acid Monohydrate Food Grade in bulk from Chinese manufacturing plants, with a batch certificate of analysis and the manufacturer’s signed safety data sheet shipped against every consignment. Tell us the grade, volume and destination port and we will come back with packing options, lead time and a delivered price.
Sources
Every value on this page was taken from one of the following public authorities. Where an authority records no verified value, this page says so rather than substituting an estimate.
- PubChem — National Library of Medicine
- NIOSH Pocket Guide to Chemical Hazards
- ILO/WHO International Chemical Safety Cards
- CAMEO Chemicals — NOAA
- ECHA Classification & Labelling Inventory
- OSHA Annotated Permissible Exposure Limits
- eCFR Title 49 §172.101 Hazardous Materials Table
Compiled September 2026. Regulatory lists and classifications change; verify against the current source text before relying on this page for a compliance decision.