A staff member from a chemical work-site in Christchurch is in hospital.

The Institute for Environmental Science and Research is carrying out testing at Bromley's Pest Control Research site, where a worker was exposed to chemicals two weeks ago.

Pest Control Research communications adviser Steve Attwood says the staff member's condition is "hopeful" but privacy has been requested by the family.

WorkSafe says today's testing is to understand the concentrations of chemicals onsite and to see if there's any Health and Safety or Environmental law breach.

The site has been closed since the incident.

Pest Control Research director Matthew O'Brien says it's too soon to speculate about what happened, but says 1080 is unlikely to be involved.

"Pest Control Research does not 1080 but it makes aerial bait for pest control pipes which contains small amounts of 1080. They are made at another location in a purpose built site designed for that."

O'Brien says they're doing everything possible to support the s

"Our thoughts and efforts are with our guy and his family and we're doing everything we can to support them, and to assist WorkSafe in their important work as well."