The main hazardous chemicals on site are acids and alkalis as well as a large variety of chemicals used in formulations.
A St John Ambulance spokeswoman said paramedics were called to the site at 3.51pm on Wednesday and a person was taken to Tauranga Hospital in a serious condition.
Graham said he was discharged on the same night.
"We take health and safety very seriously and we have robust procedures in place to protect our staff and the community, and there is no potential risk of harm," Graham said.
A WorkSafe spokesman said they were made aware of the incident and were making inquiries to identify their next steps.
The plant on Totara St was at the heart of the Mount Maunganui industrial area and would continue to operate as normal.
IXOM Mount Maunganui had been designated an upper-tier Major Hazard Facility by WorkSafe and was required to meet the requirements of the Health and Safety at Work (Major Hazard Facilities) Regulations 2016.
The main hazardous chemicals on site
• Acids: Sulphuric acid, phosphoric acid, hydrochloric, nitric acid.
• Alkalis: sodium hydroxide, sodium hypochlorite, caustic potash, sodium hydrosulphite and sodium hydrosulphide.
• Oxidisers: Hydrogen peroxide and chlorine gas. There are also a large variety of chemicals used in formulations.