ChemSplash 1 versus ChemSplash 2 versus Tychem 2000 and 4000, by the published data

How do ChemSplash 2, Tychem 2000 and Tychem 4000 compare on the same chemicals?

All three publish ASTM F739 permeation results, and the chemicals below appear on all three sheets. F739 clamps the fabric between a chemical and a detector and reports the time until the chemical comes through at a set rate. The rate matters: ASTM’s own summary says the method’s standardized breakthrough is the time the permeation rate reaches 0.1 µg/cm²/min, and that a normalized breakthrough at 1.0 µg/cm²/min may also be reported. DuPont’s table is at 0.1 (its legend reads “BT0.1 Normalized breakthrough time at 0.1 µg/cm²/min”); Enviroguard’s ChemSplash 2 table says “Using BT criteria of 1.0 µg/cm²/min.” The stricter 0.1 point is reached sooner, so a Tychem minute is earned against a tighter test than a ChemSplash 2 minute, and the columns are shown side by side only to read the pattern, not to rank the numbers.

Read down the table and the three fabrics sort themselves. Against 50% caustic and concentrated sulfuric acid, none of them breaks through in eight hours. Against the fast solvents at the bottom, dichloromethane, tetrahydrofuran, carbon disulfide, toluene, all three fail inside ten minutes. The middle of the table is where the sheets differ: Tychem 2000 is immediate on every solvent and gas on this list, and DuPont’s own count, more than 40 chemicals at 30 minutes or better, is the smallest of the three; Tychem 4000 and ChemSplash 2 each hold some of the solvents and gases and lose others, and not the same ones. For a specific chemical the only safe reading is the row for that chemical, on the manufacturer’s current sheet, at the manufacturer’s stated threshold, against the length of the task.

Where does ChemSplash 1 fit?

Nowhere on that table, because its sheet does not run F739. ChemSplash 1 is tested to ISO 6530 / EN 368, the European liquid penetration test, whose full title on the ChemSplash 2 sheet is Protective clothing, Protection against liquid chemicals, Test method for resistance of materials to penetration by liquids: a measured volume of liquid is applied at a set flow rate and the result is reported as penetration, repellency and absorption indices, which the ChemSplash 1 sheet reports as classes. The sheet prints penetration Class 3 on all nine liquids tested, n-heptane, dichloromethane, toluene, isopropanol, 50% sodium hydroxide, 36 to 37% hydrochloric acid, 48 to 50% hydrofluoric acid, JP-8 jet fuel and 96% sulfuric acid, with repellency Class 3 for the acids and caustic, Class 2 for isopropanol and JP-8, and Class 1 for heptane, dichloromethane and toluene; the catalog adds an EN 374-3 chemical penetration pass. A penetration class says the liquid did not run through the fabric in the test; it says nothing about how long the chemical takes to permeate through intact fabric, which is what the Tychem numbers measure, and the Tychem pages do not print an ISO 6530 result. The manufacturer’s own positioning is the honest one: ChemSplash 1 is the breathable splash suit (MVTR over 3,000 g/m²/24 h, hydrostatic head 226 cm) for manufacturing, emergency response and environmental cleanup where the threat is splash, and ChemSplash 2 is the step up for aggressive chemicals, acids and caustics with the F903 and F739 data to show it.

Does a penetration pass mean the chemical will not get through?

No. ASTM F903 holds the liquid against the outside of the fabric under pressure for a set time and reports whether liquid was seen on the other side; ASTM’s summary of the method says plainly that in some cases significant amounts of hazardous materials will permeate specimens that pass the penetration tests, and points to F739 for permeation. ChemSplash 2’s catalog table shows it in one row: toluene is an F903 pass and a 4-minute F739 breakthrough.

What about seams, zippers and the storm flap?

All the figures above are fabric swatches. DuPont states that in many cases seams and closures have shorter breakthrough times and higher permeation rates than the fabric, and carries a specific warning that serged and bound seams are degraded by some hazardous liquid chemicals, such as strong acids, and should not be worn when those chemicals are present; the QC127B and SL127B coveralls listed here have bound seams. Enviroguard’s answer on the ChemSplash side is tape: every ChemSplash 2 style is taped, with a storm flap over the zipper sealed by pressure-sensitive tape, and ChemSplash 1 comes in a taped YT version with a red stripe to tell it from the serged YS. For a liquid that runs, the seam and the zipper are the path, and the hazard assessment should ask the manufacturer for seam data rather than assume the fabric number.

What do the physical numbers say?

Only the tests both manufacturers ran line up. Basis weight is ASTM D3776 on all three sheets that print it: Tychem 2000 2.5 oz/yd², ChemSplash 2 2.9, Tychem 4000 3.6, and ChemSplash 1 prints none. Burst is not the same test: DuPont prints Mullen burst (ASTM D3786) in psi, 68 and 71, while Enviroguard prints ball burst (ASTM D751) in pounds, 52, and those cannot be converted into each other. Grab tensile is ASTM D5034 on both: Tychem 2000 39 and 43 lbf, Tychem 4000 44 and 48 lbf, ChemSplash 2 51.2 and 36.2 lb, machine and cross direction; ChemSplash 1 prints an ISO 13934-1 strip tensile in newtons instead. Flammability: DuPont prints 16 CFR 1610 Class 1 for both grades, a wearing-apparel classification and not a flame-resistance rating; the ChemSplash 1 catalog prints an EN 1146 pass and neither ChemSplash sheet claims FR.