2-Propanol: Isopropanol SDS and GHS Classification: H225, H319, H336 and Label Duties by Market

Safety data sheet authoring for 2-propanol (CAS 67-63-0, EC 200-661-7) begins with the harmonised entry under Regulation (EC) No 1272/2008 Annex VI, index 603-117-00-0. The classification for the neat solvent is Flam. Liq. 2 H225, Eye Irrit. 2 H319, and STOT SE 3 H336. H225 communicates that the liquid is highly flammable and the vapour is explosive; H319 communicates serious eye irritation; H336 communicates possible drowsiness or dizziness after short exposure. The label duty for the same product is not identical across markets. A 16-section SDS under CLP Article 31 and Annex II reports intrinsic values—closed-cup flash point 12 °C, initial boiling point 82.5 °C at 101.3 kPa, vapour pressure 4.4 kPa at 20 °C, lower explosive limit 2.0 vol%, upper explosive limit 12.7 vol%—while the immediate package label is selected according to the legal route to the user. In industrial drums, the full H225/H319/H336 text is placed with signal word Danger and pictograms GHS02 and GHS07. In transport, the package displays a Class 3 flammable liquid label under UN 1219, without the eye irritation and central nervous system statements. In pharmaceutical and consumer routes, text may be modified by sector-specific regulations. The separation between SDS content and label deployment prevents a single document from being applied mechanically across all containers.

How the Closed-Cup Flash Point and Minimum Ignition Energy Drive H225 Area Classification

Under CLP Annex I Part 2, category 2 flammability includes liquids with flash point below 23 °C and initial boiling point above 35 °C. Isopropanol meets this criterion because ISO 3679:2022 closed-cup testing returns 12 °C and the boiling point at 101.3 kPa is 82.5 °C. The flammability envelope is wide: lower explosive limit 2.0 vol% and upper explosive limit 12.7 vol% at 25 °C. Published minimum ignition energy for isopropanol vapour is approximately 0.65 mJ, a value low enough that a static discharge from a non-grounded stainless steel lance, an ungrounded conductive liner, or a polyethylene funnel can initiate vapour ignition in the flammable range. In a drum-transfer room handling 200 L HDPE containers, the area electrical classification under IEC 60079-10-1 is typically Zone 1 or Zone 2, depending on ventilation effectiveness, and fixed gas detection loops to IEC 60079-29-1 are set to alarm at 20 % and 40 % LEL. The corresponding label precautionary statements P210, P233, P240, P241, P242, P243, and P403+P235 are not advisory; they reflect the low ignition energy and the persistence of vapour in poorly ventilated sumps. A storage classification under NFPA 30 places 2-propanol in Class IB flammable liquid, which restricts container size and spill-containment configuration in unprotected areas. This engineering boundary is omitted from the GHS label but is explicit in the SDS Section 9 and Section 7 data.

Precautionary statement selection for H319 and H336 follows Annex IV of CLP. For H319, the label carries P264, P280, P305+P351+P338, and P337+P313. The eye-wash provision is not a label-only duty; production dispensing stations with open dip tubes are equipped with eye wash equipment conforming to ANSI/ISEA Z358.1-2014, with water delivery at 1.5 L/min for at least 15 minutes. H336 adds P261, P271, P304+P340, and P312. The STOT single exposure category 3 basis is central nervous system depression at high vapour concentrations, not a chronic neurotoxic effect. Occupational exposure benchmarks show the regulatory spread: the EU indicative 8-hour TWA is 400 ppm and the 15-minute STEL is 500 ppm; OSHA retains 400 ppm TWA in 29 CFR 1910.1000 Table Z-1; the ACGIH TLV is 200 ppm TWA and 400 ppm STEL. For ordinary closed-loop transfer, a typical time-weighted average remains below 100 ppm, but manual cleaning of a 10 m³ vessel with a stagnant heel can generate breathing-zone concentrations above 500 ppm if the manway is opened before forced ventilation has exchanged the headspace. In that case, the H336 label duty is supplemented by the SDS Section 8 requirement for supplied-air respiratory protection selected under EN 529, or an A-type organic vapour cartridge with a particulate prefilter for short tasks. The label text does not specify any numerical exposure limit; the SDS must be consulted for that operational boundary.

Mixture classification for downstream formulations follows the same GHS entry only if the concentration crosses the generic concentration limits. A waterborne cleaning concentrate containing 15 wt% 2-propanol often carries H319 but may not carry H225 if the mixture flash point remains above 23 °C and may not carry H336 if the concentration is below the STOT SE 3 generic limit. This creates a visible difference between the raw-material label and the formulation label. A formulator must not copy the raw-material SDS Section 2 into the mixture SDS without first applying the mixture classification rules of CLP Annex I Part 1 and Part 3.

Label Duties by Market in the EU, US, Canada, and Transport Segments

The GHS classification is harmonised, but the legal instrument that converts it into a label differs. In the EU/EEA, Regulation (EC) No 1272/2008 Title III and Article 17 require the label elements on the immediate package and on the outer package. In the United States, 29 CFR 1910.1200 Appendix C uses the same signal word and hazard statements, but the supplier must add product identifier, name, address, and telephone number; US OSHA does not use the EU index number. Canadian WHMIS 2015 under SOR/2015-17 follows GHS; the SDS is 16-section, and the bilingual requirement for labels applies to the outer package. For road and sea transport, the label is the Class 3 flammable liquid label for UN 1219, Packing Group II, under ADR 5.2.2.2 and the IMDG Code. The transport label does not show H319 or H336; it communicates the higher-priority flammability hazard. A 200 L drum in EU warehousing therefore carries both the transport Class 3 label and the CLP GHS label, whereas the IBC label on a dedicated returnable container may be plate-mounted with the approved UN marking and the Class 3 placard only.

When packaged as an aerosol, the transport label changes from UN 1219 to UN 1950 Aerosols, Class 2.1, and the GHS label may include the additional flammability hazard of the propellant. A consumer aerosol containing isopropanol and liquefied petroleum gas carries H222 or H223 for the mixture rather than H225, while H319 and H336 remain only if the respective concentration thresholds are met. The can label must also comply with CLP Annex II and the labelling requirements of the Aerosol Dispensers Directive 75/324/EEC.

When 2-Propanol Enters Pharmaceutical Processing as a Class 3 Residual Solvent

Pharmaceutical grades of 2-propanol do not eliminate the worker-facing SDS, but the product destination changes certain label duties and acceptance criteria. The European Pharmacopoeia monograph for isopropyl alcohol specifies a content of 99.0–100.5 % v/v and a relative density of 0.785–0.786 g/cm³ at 20 °C. ICH Q3C lists 2-propanol as a Class 3 residual solvent with a permitted daily exposure of 50 mg/day. In an API crystallization and drying sequence, a final wet cake containing 0.8 wt% isopropanol is dried at 40 °C under 25 kPa absolute until headspace GC-FID per USP 467 shows less than the limit corresponding to a 200 mg daily dose. The solvent drum in the warehouse still carries the GHS label with H225, H319, H336, but the finished pharmaceutical label does not. The reason is that the patient-facing text is governed by the summary of product characteristics and good manufacturing practice, not by the CLP classification of an input solvent. A drug product containing residual isopropanol at 0.05 wt% does not require H336 on the patient leaflet; the residual solvent is regulated as an impurity and is verified by a validated pharmacopoeial method. This is a market-specific label duty gap that is frequently missed when downstream formulators copy the raw-material SDS into product documentation.

At plant scale, the distillation recovery of used isopropanol operates below atmospheric flash point but remains within the flammability limits if air enters the vacuum receiver. A column overhead at 50 mmHg and 38 °C is below the closed-cup flash point of 12 °C, but the lower explosive limit is concentration-based, not temperature-based. The vacuum pump discharge is therefore routed to a thermal oxidizer with combustion chamber temperature above 760 °C and a residence time of 0.5 s. In the storage tank farm, nitrogen blanketing at 0.2 bar gauge keeps the tank headspace below 20 % LEL, and the conservation vent is sized to API 2000. These process controls are not communicated on the GHS label; they arise from the SDS Section 7 and the site’s explosive atmosphere safety assessment under Directive 1999/92/EC. The label duties by market therefore remain the simple but legally binding set of signal word, pictograms, hazard statements, and precautionary statements tied to H225, H319, and H336; the deeper industrial controls are documented in the SDS and the installation’s explosion protection document.