ATMI Achieves ISO 14001 Environmental Certification; Confirms Global Semiconductor Environmental Leadership Role.

Business Editors

DANBURY, Conn.--(BUSINESS WIRE)--June 6, 2000

ATMI, Inc. (Nasdaq: ATMI), today announced that it holds a global ISO-14001 Certificate, with six of its sites worldwide now certified under the ATMI banner to be in conformance with ISO-14001. ISO-14000 is the global series of standards for environmental management systems, audits, performance, evaluation, and life cycle assessment to promote greater environmental awareness while reducing environmental effects of a company's operations.

ATMI is significantly contributing to world ecology with its environmentally-focused product lines -- abatement and treatment products; comprehensive gas sensing and monitoring; sub-atmospheric gas storage and delivery systems -- for the semiconductor industry.

Only a few semiconductor companies have passed these demanding criteria to be certified to this international environmental management standard. ATMI is now one of the select few within the semiconductor industry, and continues its environmental leadership with ISO-14000 certifications and recommendations that attest to ATMI's operations reaching the highest environmental standards at:

- Mesa, Arizona - Specialty Epitaxial Services, Silicon

- Phoenix, Arizona - Specialty Epitaxial Services, III-V

- San Jose, California - Environmental Systems

- Danbury, Connecticut - Sub-Atmospheric Gas Operations

- Minneapolis, Minnesota - Critical Liquids Packaging &

Dispensing Systems

- Burnet, Texas - Source CVD and Photolithography Ancillary

Materials

With ISO-14001, ATMI demonstrates that it is certified as environmentally aware. Under the ISO- 14000 guidelines, which are patterned after the ISO-9000 quality standards, certification indicates that all business operations are scrutinized for environmentally aware resource use, structured recycling operations, and recognition in manufacturing and production of reducing costs by limiting raw material resource use.

Doug Neugold, ATMI President, said, "ATMI -- one of the most environmentally aware companies in the industry -- is committed to producing responsible and sustainable semiconductor manufacturing solutions using environmental technologies and services. Earning ISO-14001 certification means establishing formal environmental systems that identify, prioritize, and minimize the environmental effects of ATMI's operations and its products. A large part of our business is devoted specifically to improving the environment. This independent evaluation of ATMI's environmentally-focused business processes is reflective of our efforts to reduce resources, reduce costs, and improve manufacturing efficiencies -- all of which can help our customers lower their costs of ownership."

Ted Shreve, ATMI's Director of Corporate Environmental, Health, and Safety Services, said, "Improving ATMI's multi-faceted operations in a way that helps the environment, enhances product quality and consistency, and reduces the raw materials cost of manufacturing is a major challenge in a global organization. ATMI's employees have worked hard to earn this independent certification of our environmentally sound management systems. Every ATMI employee, no matter where in the world, receives training promoting environmental awareness and familiarity with our environmental management systems."

ATMI provides specialty materials and related equipment and services to the worldwide semiconductor industry. Related equipment includes materials packaging systems, delivery systems, sensors, and a full line of environmental equipment. Services include materials management, equipment servicing, and thin film deposition.

Statements which are not historical information are forward looking, and involve risks and uncertainties, including, but not limited to: changes in semiconductor industry growth or ATMI's markets; competition, problems, or delays developing and commercializing new products; problems or delays in integrating acquired operations and businesses into ATMI; and other factors discussed in ATMI's filings with the Securities and Exchange Commission. Such risks and uncertainties could cause actual results to differ from those projected.