11 laboratories in United States are accredited by A2LA under ISO/IEC 17025 to perform ASTM D4221 testing. From the accredited scope text: “ASTM D4221 Dispersive Characteristics of Clay Soil by Double Hydrometer ASTM D4318/D4318M Liquid Limit, Plastic Limit, and Plasticity Index of Soils” “ASTM D4221 Dispersive Properties of Soil by Double Hydrometer ASTM D4318; TxDOT 104E, 105E,106E Liquid Limit, Plastic Limits & Plasticity Index of Soils ASTM D4373 Rapid Determination of Carbonate Con” “ASTM D4221 Dispersive Characteristics of Clay Soil by Double Hydrometer ASTM D4546 One-Dimensional Swell or Settlement Properties of Cohesive Soils ASTM D4647/D4647M Identification and Classification” “ASTM D4221 Dispersive Characteristics of Clay Soil by Double Hydrometer ASTM D4253 Maximum Index Density and Unit Weight of Soils Using a Vibratory Table ASTM D4254 Minimum Index Density and Unit Weig”
Houston, TX, US
ASTM D4221 Dispersive Properties of Soil by Double Hydrometer ASTM D4318/D4318M Liquid Limit, Plastic Limits and Plasticity Index of Soils ASTM D4546 One-Dimensional Swell or Collapse of Soils ASTM D5102/D5102M Unconfined Compression
Houston, TX, US
ASTM D4221 Dispersive Characteristics of Clay Soil by Double Hydrometer ASTM D4318 Liquid Limit, Plastic Limit and Plasticity Index of Soils ASTM D4546 One Dimensional Swell of Settlement Potential of Cohesive Soils ASTM D4718 Correction
Houston, TX, US
ASTM D4221 Dispersive Characteristics of Clay Soil by Double Hydrometer ASTM D4253 Maximum Index Density and Unit Weight of Soils Using a Vibratory Table ASTM D4254 Minimum Index Density and Unit Weight of Soils and Calculation of Relat
Humble, TX, US
ASTM D4221 Dispersive Characteristics of Clay Soil by Double Hydrometer ASTM D4546 One-Dimensional Swell or Settlement Properties of Cohesive Soils ASTM D4647/D4647M Identification and Classification of Dispersive Clay Soils by the Pinho
Houston, TX, US
ASTM D4221 Dispersive Characteristics of Clay Soil by Double Hydrometer ASTM D4318/D4318M Liquid Limit, Plastic Limit, and Plasticity Index of Soils
Houston, TX, US
ASTM D4221 Dispersive Characteristics of Clay Soil by Double Hydrometer ASTM D4318 (withdrawn 2026) Liquid Limit, Plastic Limit, and Plasticity Index of Soils ASTM D4546 One-Dimensional Swell or Collapse of Cohesive Soils
Sugar Land, TX, US
ASTM D4221 Dispersive Characteristics of Clay Soils by Double Hydrometer ASTM D4318 Liquid Limit, Plastic Limit, and Plasticity Index of Soils ASTM D4546 One-Dimensional Swell/Settlement Potential of Cohesive Soils ASTM D4643 Water Con
Houston, TX, US
ASTM D4221 Dispersive Characteristics of Clay Soil by Double Hydrometer ASTM D4318 Liquid Limit, Plastic Limit and Plasticity Index of Soils ASTM D4546 One-Dimensional Swell-Settlement Potential of Cohesive Soils ASTM D4643 Determination
Suite U Houston, TX, US
ASTM D4221 Dispersive Characteristics of Clay Soil by Double Hydrometer ASTM D4318 Liquid Limit, Plastic Limit, and Plasticity Index of Soils ASTM D4546 One-Dimensional Swell or Collapse of Cohesive Soils ASTM D4767 Consolidated Undrai
Corpus Christi, TX, US
ASTM D4221 Dispersive Properties of Soil by Double Hydrometer ASTM D4318; TxDOT 104E, 105E,106E Liquid Limit, Plastic Limits & Plasticity Index of Soils ASTM D4373 Rapid Determination of Carbonate Content of Soils ASTM D4546 One-
Houston, TX, US
ASTM D4221 Dispersive Characteristics of Clay Soil by Double Hydrometer ASTM D4318 Liquid Limit, Plastic Limit, and Plasticity Index of Soils ASTM D4546 One-Dimensional Swell or Collapse of Soils ASTM D4643 Determination of Water (Moistu
This page is a fixed slice of the register: every ASTM D4221 scope we hold for United States. Search narrows it further by city, accreditation body, or a term from the scope text itself.
Search labs in United StatesAmerican Association for Laboratory Accreditation (A2LA) is the primary accreditation body issuing ISO/IEC 17025 accreditation for testing laboratories in United States.
ISO/IEC 17025 is the international standard for the competence of testing and calibration laboratories. Accreditation to this standard provides independent confirmation that a laboratory operates a quality management system and is technically competent to produce valid results within its declared scope.