The purpose of this project was to develop a quality control (QC) and quality assurance (QA) document for the EPA Level 1 environmental assessment biological testing program. This manual, developed as part of this program, supplements the Level 1 biological testing procedures manual (1). Although the Level 1 procedures manual presents detailed information on sample preparation, bioassay procedures, data evaluation, and sample ranking, the Level 1 manual describes the role and recommended use of laboratory QC and QA procedures in the Level 1 biological testing program. IERL-RTP's QA audit sample program is presented in the QC/QA manual. In this program, audit samples are made available to laboratories wishing to verify proficiency in conducting Level 1 bioassays. Also described is the documentation required for test material sampling, processing, storage, and disposal. The manual identifies protocol steps for each Level 1 health effects bioassay and describes the QC and documentation procedures required to meet the U.S. Food and Drug Administration's Good Laboratory Practice Regulations. In addition to recommendations for QC and QA procedures, the document supplies sample forms which may be used by laboratories that have not developed their own standard data recording forms. QC and QA procedures vary somewhat between laboratories, and this document serves as a model, but should not be viewed as the only acceptable approach to QC and QA. These QC and QA procedures are not intended to restrict test performance or improvements in study designs, but are critical to maintain uniformity of data generation, documentation, and interpretation.