Chemical Safety Data Sheet MSDS / SDS
Diethyl squarate
Revision Date:2026-03-21Revision Number:1
Product identifier
- Product name: Diethyl squarate
- CBnumber: CB1106356
- CAS: 5231-87-8
- Synonyms: 3,4-DIETHOXYCYCLOBUT-3-ENE-1,2-DIONE;Diethyl squarate in stock Factory
Relevant identified uses of the substance or mixture and uses advised against
- Relevant identified uses: For R&D use only. Not for medicinal, household or other use.
- Uses advised against: none
Company Identification
- Company: Chemicalbook
- Address: Building 1, Huihuang International, Shangdi 10th Street, Haidian District, Beijing
- Telephone: 010-86108875
GHS Label elements, including precautionary statements
-
Symbol(GHS)
- Signal wordDanger
P280 Wear protective gloves/protective clothing/eye protection/face protection.
P302+P352 IF ON SKIN: wash with plenty of soap and water.
P305+P351+P338 IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.
Hazard statements
H315 Causes skin irritation
H317 May cause an allergic skin reaction
H319 Causes serious eye irritation
H334 May cause allergy or asthma symptoms or breathing difficulties if inhaled
H335 May cause respiratory irritation
Substance
- Product name: Diethyl squarate
- Synonyms: 3,4-DIETHOXYCYCLOBUT-3-ENE-1,2-DIONE;Diethyl squarate in stock Factory
- CAS: 5231-87-8
- MF: C8H10O4
- MW: 170.16
Eye Contact
Rinse immediately with plenty of water, also under the eyelids, for at least 15 minutes. Get medical attention.
Skin Contact
Wash off immediately with plenty of water for at least 15 minutes. Get medical attention.
Inhalation
Remove to fresh air. If not breathing, give artificial respiration. Get medical attention.
Ingestion
Do NOT induce vomiting. Get medical attention.
Most important symptoms and effects
May cause allergy or asthma symptoms or breathing difficulties if inhaled. May cause allergic skin reaction. Symptoms of allergic reaction may include rash, itching, swelling, trouble breathing, tingling of the hands and feet, dizziness, lightheadedness, chest pain, muscle pain or flushing
Self-Protection of the First Aider
Ensure that medical personnel are aware of the material(s) involved, take precautions to protect themselves and prevent spread of contamination.
Notes to Physician
Treat symptomatically.
Suitable Extinguishing Media
Water spray, carbon dioxide (CO2), dry chemical, alcohol-resistant foam.
Extinguishing media which must not be used for safety reasons
No information available.
Specific Hazards Arising from the Chemical
Thermal decomposition can lead to release of irritating gases and vapors.
Protective Equipment and Precautions for Firefighters
As in any fire, wear self-contained breathing apparatus pressure-demand, MSHA/NIOSH (approved or equivalent) and full protective gear. Thermal decomposition can lead to release of irritating gases and vapors.
NFPA 704
2
1
0
| HEALTH | 2 | Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury (e.g. diethyl ether, ammonium phosphate, iodine) | |
| FIRE | 1 | Materials that require considerable preheating, under all ambient temperature conditions, before ignition and combustion can occur. Includes some finely divided suspended solids that do not require heating before ignition can occur. Flash point at or above 93.3 °C (200 °F). (e.g. mineral oil, ammonia) | |
| REACT | 0 | Normally stable, even under fire exposure conditions, and is not reactive with water (e.g. helium,N2) | |
| SPEC. HAZ. |
Personal Precautions
Ensure adequate ventilation. Use personal protective equipment as required.
Environmental Precautions
Should not be released into the environment.
Methods for Containment and Clean Up
Soak up with inert absorbent material. Keep in suitable, closed containers for disposal.
Refer to protective measures listed in Sections 8 and 13.
Refer to protective measures listed in Sections 8 and 13.
Handling
Use only under a chemical fume hood. Wear personal protective equipment/face protection. Do not get in eyes, on skin, or on clothing. Avoid ingestion and inhalation. Wash hands before breaks and immediately after handling the product.
Storage
Keep container tightly closed in a dry and well-ventilated place. Keep refrigerated. Keep under nitrogen.
Specific Use(s)
Use in laboratories
Control Parameters
Monitoring methods
BS EN 14042:2003 Title Identifier: Workplace atmospheres. Guide for the application and use of procedures for the assessment of exposure to chemical and biological agents. MDHS70 General methods for sampling airborne gases and vapours MDHS 96
Volatile organic compounds in air - Laboratory method using pumped solid sorbent tubes, solvent desorption and gas chromatography
Volatile organic compounds in air - Laboratory method using pumped solid sorbent tubes, solvent desorption and gas chromatography
Exposure Controls
Engineering Measures
Use only under a chemical fume hood. Ensure that eyewash stations and safety showers are close to the workstation location.
Wherever possible, engineering control measures such as the isolation or enclosure of the process, the introduction of process or equipment changes to minimise release or contact, and the use of properly designed ventilation systems, should be adopted to control hazardous materials at source.
Wherever possible, engineering control measures such as the isolation or enclosure of the process, the introduction of process or equipment changes to minimise release or contact, and the use of properly designed ventilation systems, should be adopted to control hazardous materials at source.
Personal protective equipment
Eye ProtectionGoggles (European standard - EN 166)
Hand Protection
Protective gloves
Inspect gloves before use.
Please observe the instructions regarding permeability and breakthrough time which are provided by the supplier of the gloves.
(Refer to manufacturer/supplier for information)
Ensure gloves are suitable for the task: Chemical compatability, Dexterity, Operational conditions, User susceptibility, e.g.
sensitisation effects, also take into consideration the specific local conditions under which the product is used, such as the danger of cuts, abrasion.
Remove gloves with care avoiding skin contamination.
Skin and body protection
| Glove material | Breakthrough time | Glove thickness | EU standard | Glove comments |
|---|---|---|---|---|
| Nitrile rubber | See manufacturers | - | EN 374 | (minimum requirement) |
| Neoprene | recommendations | |||
| Natural rubber | ||||
| PVC |
Inspect gloves before use.
Please observe the instructions regarding permeability and breakthrough time which are provided by the supplier of the gloves.
(Refer to manufacturer/supplier for information)
Ensure gloves are suitable for the task: Chemical compatability, Dexterity, Operational conditions, User susceptibility, e.g.
sensitisation effects, also take into consideration the specific local conditions under which the product is used, such as the danger of cuts, abrasion.
Remove gloves with care avoiding skin contamination.
Wear appropriate protective gloves and clothing to prevent skin exposure
Respiratory Protection
When workers are facing concentrations above the exposure limit they must use appropriate certified respirators.
To protect the wearer, respiratory protective equipment must be the correct fit and be used and maintained properly
Large scale/emergency use
To protect the wearer, respiratory protective equipment must be the correct fit and be used and maintained properly
Use a NIOSH/MSHA or European Standard EN 136 approved respirator if exposure limits are exceeded or if irritation or other symptoms are experienced
Recommended Filter type: Organic gases and vapours filter Type A Brown conforming to
EN14387
Small scale/Laboratory use
Recommended Filter type: Organic gases and vapours filter Type A Brown conforming to
EN14387
Use a NIOSH/MSHA or European Standard EN 149:2001 approved respirator if exposure limits are exceeded or if irritation or other symptoms are experienced.
Recommended half mask:- Valve filtering: EN405; or; Half mask: EN140; plus filter, EN 141
When RPE is used a face piece Fit Test should be conducted
Recommended half mask:- Valve filtering: EN405; or; Half mask: EN140; plus filter, EN 141
When RPE is used a face piece Fit Test should be conducted
Hygiene Measures
Handle in accordance with good industrial hygiene and safety practice.
Environmental exposure controls
No information available.
Information on basic physicochemical properties
- ColourClear yellow to light brownish
- AppearanceYellow
- Physical StateLiquid
- OdorNo information available
- Odor ThresholdNo data available
- pHNo information available
- Melting Point/RangeNo data available
- Softening PointNo data available
- Boiling Point/Range95 °C / 203 °
F @ 0.1 mmHg - Flash Point> 110 °C / > 230 °F Method - No information available
- Evaporation RateNo data available
- Flammability (solid,gas)Not applicable Liquid
- Explosion LimitsNo data available
- Vapor PressureNo data available
- Vapor Density5.8 7 (Air = 1.0)
- Specific Gravity / Density1.150
- Bulk DensityNot applicable Liquid
- Water SolubilityInsoluble
- Solubility in other solventsNo information available
- Partition Coefficient (n-octanol/water)No data available
- Autoignition TemperatureNo data available
- Decomposition TemperatureNo data available
- ViscosityNo data available
- Explosive PropertiesNo information available
- Oxidizing PropertiesNo information available
- Molecular FormulaC8 H10 O4
- Molecular Weight170.16
Stability
Stable under normal conditions.
Hazardous Reactions
None under normal processing.
Hazardous Polymerization
Hazardous polymerization does not occur.
Conditions to Avoid
Incompatible products. Excess heat.
Materials to avoid
Strong oxidizing agents. Strong bases. Acids.
Hazardous Decomposition Products
Carbon monoxide (CO). Carbon dioxide (CO2).
Product Information
See actual entry in RTECS for complete information.
(a) acute toxicity;
(b) skin corrosion/irritation;
Category 2
(c) serious eye damage/irritation;
Category 2
(d) respiratory or skin sensitization;
RespiratoryCategory 1
Skin
Category 1
May cause sensitization by skin contact
May cause sensitization by skin contact
(e) germ cell mutagenicity;
No data available
(f) carcinogenicity;
No data available
There are no known carcinogenic chemicals in this product
There are no known carcinogenic chemicals in this product
(g) reproductive toxicity;
No data available
(h) STOT-single exposure;
Category 3
Results / Target organs
Respiratory system
(i) STOT-repeated exposure;
No data available
Target Organs
No information available.
(j) aspiration hazard;
No data available
Other Adverse Effects
The toxicological properties have not been fully investigated.
Symptoms / effects,both acute and delayed
Symptoms of allergic reaction may include rash, itching, swelling, trouble breathing, tingling of the hands and feet, dizziness, lightheadedness, chest pain, muscle pain or flushing
Ecotoxicity effects
Contains no substances known to be hazardous to the environment or that are not degradable in waste water treatment plants.
Persistence and Degradability
Persistence
Insoluble in water, Persistence is unlikely, based on information available.
Bioaccumulative Potential
May have some potential to bioaccumulate
Mobility in soil
Spillage unlikely to penetrate soil The product is insoluble and sinks in water The product contains volatile organic compounds (VOC) which will evaporate easily from all surfaces Is not likely mobile in the environment due its low water solubility Will likely be mobile in the environment due to its volatility
Endocrine Disruptor Information
This product does not contain any known or suspected endocrine disruptors
Persistent Organic Pollutant
This product does not contain any known or suspected substance
Ozone Depletion Potential
This product does not contain any known or suspected substance
Other Information
Waste codes should be assigned by the user based on the application for which the product was used. Do not empty into drains.
| Waste from Residues/Unused | Waste is classified as hazardous. Dispose of in accordance with the European Directives |
|---|---|
| Products | on waste and hazardous waste. Dispose of in accordance with local regulations. |
| Contaminated Packaging | Dispose of this container to hazardous or special waste collection point. |
Road and Rail Transport
Not Regulated
IMDG/IMO
Not regulated
IATA
Not regulated
Special Precautions for User
No special precautions required
International Inventories
X = listed, China (IECSC), Europe (EINECS/ELINCS/NLP), U.S.A. (TSCA), Canada (DSL/NDSL), Philippines (PICCS), Japan (ENCS), Japan (ISHL), Australia (AICS), Korea (KECL).
| Component | The Inventory of Hazardous Chemicals (2015 Edition) | List of dangerous goods GB 12268 - 2012 | TCSI | IECSC | EINECS | TSCA | DSL | PICCS | ENCS | ISHL | AICS | KECL |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 3,4-Diethoxy-3-cyclobu tene-1,2-dione | - | - | X | - | - | - | - | - | - | X | - | - |
National Regulations
Prepared By
Health, Safety and Environmental Department
Creation Date
28-Oct-2009
Revision Date
14-Sep-2025
Revision Summary
Not applicable.
Training Advice
Chemical hazard awareness training, incorporating labelling, Safety Data Sheets (SDS), Personal Protective Equipment (PPE) and hygiene.
Use of personal protective equipment, covering appropriate selection, compatibility, breakthrough thresholds, care, maintenance, fit and standards.
First aid for chemical exposure, including the use of eye wash and safety showers.
Use of personal protective equipment, covering appropriate selection, compatibility, breakthrough thresholds, care, maintenance, fit and standards.
First aid for chemical exposure, including the use of eye wash and safety showers.
Legend
CASChemical Abstracts Service
TSCA
United States Toxic Substances Control Act Section 8(b)
Inventory
EINECS/ELINCS
Inventory
European Inventory of Existing Commercial Chemical
Substances/EU List of Notified Chemical Substances
DSL/NDSL
Substances/EU List of Notified Chemical Substances
Canadian Domestic Substances List/Non-Domestic
Substances List
PICCS
Substances List
Philippines Inventory of Chemicals and Chemical Substances
ENCS
Japanese Existing and New Chemical Substances
IECSC
Chinese Inventory of Existing Chemical Substances
AICS
Australian Inventory of Chemical Substances
KECL
Korean Existing and Evaluated Chemical Substances
NZIoC
New Zealand Inventory of Chemicals
WEL
Workplace Exposure Limit
TWA
Time Weighted Average
ACGIH
American Conference of Governmental Industrial Hygienists
IARC
International Agency for Research on Cancer
DNEL
Derived No Effect Level
PNEC
Predicted No Effect Concentration
RPE
Respiratory Protective Equipment
LD50
Lethal Dose 50%
LC50
Lethal Concentration 50%
EC50
Effective Concentration 50%
NOEC
No Observed Effect Concentration
POW
Partition coefficient Octanol:Water
PBT
Persistent, Bioaccumulative, Toxic
vPvB
very Persistent, very Bioaccumulative
ICAO/IATA
International Civil Aviation Organization/International Air
Transport Association
IMO/IMDG
Transport Association
International Maritime Organization/International Maritime
Dangerous Goods Code
ADR
Dangerous Goods Code
European Agreement Concerning the International Carriage of
Dangerous Goods by Road
MARPOL
Dangerous Goods by Road
International Convention for the Prevention of Pollution from
Ships
OECD
Ships
Organisation for Economic Co-operation and Development
ATE
Acute Toxicity Estimate
BCF
Bioconcentration factor
VOC
(Volatile Organic Compound)
Key literature references and sources for data
https://echa.europa.eu/information-on-chemicals
Suppliers safety data sheet, Chemadvisor - LOLI, Merck index, RTECS
Suppliers safety data sheet, Chemadvisor - LOLI, Merck index, RTECS
Disclaimer
The information provided in this Safety Data Sheet is correct to the best of our knowledge, information and belief at the date of its publication. The information given is designed only as a guidance for safe handling, use, processing, storage, transportation, disposal and release and is not to be considered a warranty or quality specification. The information relates only to the specific material designated and may not be valid for such material used in combination with any other materials or in any process, unless specified in the text
Disclaimer:
The information in this MSDS is only applicable to the specified product, unless otherwise specified, it is not applicable to the mixture of this product and other substances. This MSDS only provides information on the safety of the product for those who have received the appropriate professional training for the user of the product. Users of this MSDS must make independent judgments on the applicability of this SDS. The authors of this MSDS will not be held responsible for any harm caused by the use of this MSDS.