Quick Answer
Yes. Mono ethylene glycol (MEG, CAS 107-21-1) is both toxic and hazardous - it is acutely toxic if ingested (GHS Acute Toxicity Category 4, oral) and classified as hazardous under global chemical safety frameworks including GHS, OSHA, and REACH. For industrial buyers, this means MEG requires proper SDS documentation, restricted handling protocols, and compliant labeling and transport declarations at every stage of the supply chain - not just careful storage on-site.
Toxicity Classification: What "Acutely Toxic" Actually Means Here
MEG's toxicity isn't about vapor exposure or skin contact in typical handling - it's almost entirely an ingestion hazard, which is somewhat unusual compared to solvents where inhalation risk dominates the safety conversation.
Once ingested, MEG is metabolized by the liver into glycolic acid and then oxalic acid. The oxalic acid is the real damage-causing agent: it crystallizes with calcium in the kidneys, leading to acute renal failure, while the accumulating acids drive severe metabolic acidosis. This progression is well established in clinical toxicology literature and is the reason antifreeze ingestion (accidental or intentional) remains a standing emergency-medicine category.
Key toxicity data points buyers should have on file:
- Oral LD50 (rat): approximately 4,700 mg/kg
- Estimated human lethal dose: roughly 1.4 mL/kg body weight (varies by source and individual factors)
- GHS classification: Acute Tox. 4 (oral) - H302, "harmful if swallowed"
That LD50 number sounds relatively mild compared to genuinely potent poisons, but the real risk driver is MEG's sweet taste combined with high-volume industrial presence - most documented poisoning cases involve accidental exposure in children or pets rather than industrial workers following SDS protocols.
Hazard Classification: Beyond Toxicity
"Hazardous" is a broader designation than "toxic," and MEG's hazard profile pulls in a few additional dimensions worth separating out for compliance purposes.
| Hazard Category | Classification | Practical Implication for Buyers |
|---|---|---|
| Acute Oral Toxicity | GHS Category 4 | SDS required; restricted labeling |
| Specific Target Organ Toxicity (repeated exposure) | STOT RE 2 | Long-term handling controls recommended |
| Flammability | Combustible liquid (not highly flammable) | Standard fire-safety storage, not explosion-proof requirements |
| Environmental Hazard | Low acute aquatic toxicity, but regulated discharge | Disposal must follow local wastewater regulations |
| Transport Classification (UN) | UN 3082 (environmentally hazardous, when applicable) | Shipping documentation and labeling requirements apply |
The STOT RE 2 classification is one that gets overlooked in casual summaries - it flags MEG as capable of causing organ damage (primarily kidney effects) through repeated or prolonged exposure, not just a single acute event, which matters for facilities running continuous glycol-handling operations rather than occasional batch use.
Regulatory Status Across Major Markets
| Regulatory Framework | Status |
|---|---|
| GHS (Global) | Acute Tox. 4, STOT RE 2 |
| OSHA (US) | Regulated under Hazard Communication Standard; PEL guidance available |
| REACH (EU) | Registered substance; restrictions apply to consumer-facing concentrations |
| China GB standards | Classified as hazardous chemical under GB 30000 series |
Buyers sourcing across multiple regions should confirm that a supplier's SDS is formatted to the destination market's specific standard - a GHS-compliant SDS from a Chinese exporter doesn't automatically satisfy OSHA's Hazard Communication Standard formatting requirements for a US-bound shipment, even though the underlying hazard data is the same.
What Buyers Should Require From Suppliers
Given MEG's classification, a legitimate industrial supplier should be able to provide, without hesitation:
- A current Safety Data Sheet (SDS) matching the destination market's regulatory format (GHS, OSHA HCS, or equivalent)
- A Certificate of Analysis (COA) confirming purity and impurity levels relevant to safe handling
- Correct UN transport classification and labeling on shipping documentation
- Clear packaging hazard labels (GHS pictograms, signal words) consistent with the SDS
A supplier who is vague about any of these, or provides an SDS that looks templated rather than substance-specific, is worth a second look before finalizing an order - this is one area where cutting corners upstream becomes a liability downstream, often at the receiving facility rather than the supplier's.
Handling and Storage Implications for Industrial Buyers
Because MEG's primary hazard is ingestion rather than inhalation or skin absorption, facility-level controls tend to focus on containment and access control rather than heavy respiratory protection:
- Sealed storage below 40°C, away from food-grade materials and consumable storage areas
- Clear hazard labeling on all containers, including decanted or intermediate storage vessels
- Spill containment measures, since MEG's water solubility means uncontained spills can migrate into drainage systems
- Restricted access in facilities where accidental ingestion risk exists (shared break areas, unlabeled containers)
FAQ
Is MEG dangerous to touch?
Skin contact with MEG carries low acute risk under normal handling - it's not a strong skin irritant or absorbed in dangerous quantities through intact skin. The primary hazard is ingestion, not dermal contact.
How much MEG is fatal if swallowed?
Estimates vary, but the commonly cited human lethal dose is roughly 1.4 mL/kg of body weight, meaning a relatively small volume can be dangerous for a child, though exact thresholds depend on individual factors and how quickly treatment is administered.
Does MEG require hazmat shipping documentation?
Yes, in many cases MEG shipments require UN classification (UN 3082 when environmentally hazardous provisions apply) and corresponding transport documentation - buyers should confirm this with their supplier and freight forwarder before shipment.
Is MEG's hazard classification the same worldwide?
The underlying GHS hazard data is broadly consistent, but the format and specific regulatory requirements (OSHA, REACH, GB standards) differ by region, so SDS documentation should match the destination market.
What should I check on a supplier's SDS before placing an order?
Confirm the SDS is dated recently, matches the specific product grade being quoted, includes correct GHS classification and UN transport number, and is formatted for your destination market's regulatory framework.
