Description

ASTM D1141 Substitute Ocean Water Salt

The reference-grade synthetic seawater mixture for corrosion testing, electrochemistry, and marine simulation.

What you’re getting

This is a pre-blended, dry powder formulation that produces substitute ocean water meeting ASTM D1141-98(2021), Formula A, Table X1.1. Just as in the spec, you will add 41.953 grams to 1 liter of deionized water, adjust pH to 8.2 with dilute NaOH, and you have a chemically-defined synthetic seawater that matches the ionic composition of average open-ocean water at 35 g/kg salinity.

The salt is granular, free-flowing, and colorless. Each batch is blended to specification and conforms to our Safety Data Sheet. For the technical background on what D1141 actually specifies, why it exists, and how it compares to natural seawater and commercial aquarium salts, see our ASTM D1141 reference page.

Why customers choose this product

Reproducibility. Natural seawater varies by location, season, depth, and biological activity, which makes it useless as a controlled test medium. D1141 fixes the chemistry so your corrosion rates, polarization curves, and coating exposures mean something across labs, dates, and operators. Read more about seawater composition variability on Wikipedia.

Pre-blended convenience. Every gram of every salt (sodium chloride, magnesium chloride hexahydrate, sodium sulfate, calcium chloride, potassium chloride, sodium bicarbonate, potassium bromide, boric acid, strontium chloride hexahydrate, and sodium fluoride) is already weighed and combined in the correct proportions. No fume hood required. No analytical balance required. No deliquescent magnesium chloride to fight with on a humid day. Open the bag, weigh out what you need, dissolve.

Cost vs. competitors. We sell this at industrial-laboratory pricing, not aquarium-hobbyist or repackaged-reagent markups. Our pricing is consistently highly competitive with fast turnaround.

Common applications

This is the same artificial seawater used by:

• ASTM G48 pitting and crevice corrosion testing on stainless steels and nickel alloys
• ASTM G31 immersion corrosion of metals
• ASTM G44 alternate immersion stress corrosion testing
• ASTM B117 salt fog cabinet exposure (when D1141 is specified instead of 5% NaCl)
• NACE TM0177 sulfide stress cracking with seawater variants
• Hydrogen embrittlement testing per ASTM F1624 when seawater electrolyte is required
• Marine coatings and antifouling research
• Electrochemical impedance spectroscopy and potentiodynamic polarization work
• Sensor and oceanographic instrument calibration
• Biological media for marine organism culturing (with appropriate sterilization and pH adjustment)
• Firefighting chemical testing
• Subsea environmental simulation

If your test method specifies “substitute ocean water,” “synthetic seawater per D1141,” or “artificial seawater,” this is the product.

Composition (per ASTM D1141, Formula A)

The dry blend produces a solution containing the following major ions when mixed at 41.953 g/L:

Total dissolved solids: approximately 35 g/kg, matching the average salinity of natural ocean water as defined by the International Council for the Exploration of the Sea.

The “Regular” formulation contains the major ions only. For applications requiring trace metal concentrations (copper, iron, manganese, zinc, lead, etc.), see our Heavy Metals version.

Preparation instructions

1. Weigh out 41.953 g of D1141 salt for each 1 L of substitute ocean water you want to prepare.
2. Dissolve in deionized or distilled water, stirring continuously. Use roughly 80% of your final volume.
3. Adjust pH to 8.2 using 0.1 N NaOH (most common) or 0.1 N HCl if needed.
4. Bring up to final volume with additional deionized water.
5. A small quantity of insoluble residue is normal and can be filtered out without affecting the dissolved chemistry.

For one US gallon (3.785 L), use approximately 158.8 g (about 5.6 oz). Detailed mixing tables for common volumes are available on our D1141 product reference page.

Quality and documentation

Every order ships with links to (and paper copies on request):

• Certificate of Analysis (COA) documenting batch composition and conformance to ASTM D1141, Formula A
• Safety Data Sheet (SDS) in 16-section GHS format

Storage: keep in a sealed container in a cool, dry location. The blend is hygroscopic. Properly stored, shelf life is at least 24 months.

About US Corrosion Services

US Corrosion Services is a Houston-based metallurgical and corrosion testing laboratory. We use this same D1141 mixture in our own work on hydrogen embrittlement, electrochemical testing, immersion corrosion, and failure analysis. We sell it because our customers kept asking where to source reproducible, lab-grade artificial seawater at a sensible price.

For technical questions or volume pricing, contact us at info@uscorrosion.com or 832-481-6600.