| Base Material | Confirm the exact grade and composition of stainless steel, brass, zinc alloy, aluminum, glass, ceramic, or plastic used in each component. | ASTM A240 covers flat-rolled stainless-steel products; ASTM B16 covers free-cutting brass rod, bar, and shapes. | Material certificates, supplier certificates, product drawings, and independent alloy or composition testing. | Terms such as “premium metal” without a grade, wall thickness, or component specification. | Request a component-level bill of materials and approve only documented material grades. |
| Corrosion Resistance | Assess resistance to humidity, bathroom chemicals, salt exposure, and galvanic corrosion between dissimilar metals. | ISO 9227 specifies neutral salt-spray testing procedures. The test is comparative and does not by itself predict service life. | Test report showing the tested product, preparation, exposure duration, evaluation method, and observed corrosion results. | A salt-spray result with no test method, sample identification, exposure duration, or acceptance criteria. | Define the environmental class and acceptance criteria before testing; do not compare unsupported “hours” claims. |
| Surface Finish and Plating | Check coating adhesion, uniformity, appearance, porosity, abrasion resistance, and resistance to household cleaners. | ISO 1456 and ISO 1457 cover electrodeposited nickel and chromium coatings on metallic substrates. | Coating specification, thickness measurements, adhesion testing, visual inspection records, and cleaner-resistance results. | Visible pinholes, uneven color, blistering, sharp edges, or a decorative coating presented as a corrosion guarantee. | Approve a golden sample and require production inspection against the same finish standard. |
| Structural Strength | Verify load capacity, wall-anchor strength, screw retention, weld quality, and resistance to repeated use. | Use the applicable product standard or a documented customer specification because requirements vary by accessory type and installation method. | Load-test reports, fixture drawings, installation instructions, weld inspection records, and sample approval. | No defined load rating, undersized anchors, weak welds, or a test performed on a different construction from the shipped product. | Test the complete installed assembly, including the supplied screws, anchors, substrate, and mounting hardware. |
| Water and Pressure Performance | For faucets, shower fittings, and water-connected products, verify leakage, pressure resistance, flow, temperature control, and connection durability. | EN 817 applies to mechanical mixing valves; ASME A112.18.1/CSA B125.1 applies to plumbing supply fittings. Select the standard appropriate to the product. | Product-specific test reports, calibrated pressure gauges, dimensional records, and traceable inspection data. | Generic leak-test claims without pressure, duration, temperature, sample quantity, or acceptance criteria. | Specify the destination-market plumbing standard and require testing at the conditions stated in that standard. |
| Water Contact Safety | For components that contact drinking water, verify material safety and restrictions on substances that may leach into water. | NSF/ANSI/CAN 61 addresses health effects of drinking-water system components, not ordinary non-water-contact accessories. | A valid product-specific certification or laboratory report covering the exact materials and intended use. | Using a general factory certificate as proof of drinking-water compliance. | Apply this requirement only where the product is connected to or contacts potable water. |
| Quality Management | Evaluate document control, incoming inspection, process control, nonconformance handling, corrective action, and final inspection. | ISO 9001 specifies requirements for a quality management system. | Current certificate, certification scope, audit records, inspection plans, calibration records, and corrective-action examples. | A certificate with an unrelated scope, expired validity, or no evidence of product-level controls. | Confirm certificate validity and audit the actual production site rather than relying on a certificate image alone. |
| Laboratory Capability | Check whether testing is performed with calibrated equipment, controlled methods, trained personnel, and traceable records. | ISO/IEC 17025 establishes competence requirements for testing and calibration laboratories. | Laboratory scope, calibration certificates, test-method documents, raw data, and sample traceability. | Uncontrolled spreadsheets, missing calibration dates, or reports that cannot identify the tested sample. | Use an accredited independent laboratory when the product risk, regulation, or customer specification requires impartial verification. |
| Manufacturing Processes | Confirm capabilities for stamping, CNC machining, casting, welding, polishing, plating, assembly, packaging, and tooling maintenance. | Process requirements should be defined in approved drawings, control plans, work instructions, and inspection criteria. | Factory tour, process flow chart, machine list, capacity records, control plan, and production samples. | Unclear subcontracting, no process ownership, inconsistent samples, or production capacity based only on verbal claims. | Identify every critical process and disclose approved subcontractors before placing a production order. |
| Traceability and Change Control | Verify that raw materials, batches, inspection results, tooling, and engineering changes can be traced to finished products. | ISO 9001 includes requirements related to documented information, operational control, and control of nonconforming outputs. | Lot codes, batch records, revision-controlled drawings, approved change notices, and retention samples. | Unannounced substitutions of materials, finishes, packaging, or components after sample approval. | Require written approval for changes affecting material, dimensions, finish, function, compliance, or the supply chain. |
| Final Inspection and Defect Control | Review dimensional checks, appearance inspection, function testing, packaging checks, and defect classification. | Use an agreed inspection plan and acceptance criteria; sampling should be based on product risk and order requirements. | Inspection checklist, measurement records, defect photographs, approved limit samples, and pre-shipment inspection reports. | Only a visual “passed” stamp, no critical-defect definition, or no record of rejected units. | Separate critical, major, and minor defects and agree the sampling plan before mass production. |
| Environmental and Chemical Compliance | Check restricted substances, packaging requirements, wastewater controls, and environmental management where required by the destination market. | ISO 14001 covers environmental management systems. RoHS applies to specified electrical and electronic equipment, not automatically to ordinary bathroom accessories. | Material declarations, applicable laboratory reports, environmental permits, wastewater records, and certification scope. | A compliance logo with no product scope, test basis, regulation version, or supporting documentation. | Map each legal requirement to the exact product and destination market before requesting evidence. |
| Packaging and Installation Support | Confirm protection against scratching, moisture, impact, missing components, and installation errors during transport and handling. | Packaging and transport tests should follow the requirements of the sales channel, shipment method, and destination market. | Packaging specification, drop or vibration test records where applicable, installation drawings, parts list, and multilingual instructions. | Unprotected polished surfaces, unclear mounting instructions, missing anchors, or inconsistent accessory kits. | Perform a packing review and installation trial using production-intent samples before shipment approval. |