AI site safety knowledge assistant.

What the assistant answers, and what it refuses

A site safety knowledge assistant is a question box on a worker’s phone that searches the contractor’s approved safety documents and replies in two or three sentences with a link to the source. Typical questions: what the exclusion zone is for this afternoon’s crane lift, which data sheet covers the epoxy in the store, what respiratory protection the cutting task needs, who holds first aid today, and how to log a near miss.

It refuses three kinds of question by design. Anything describing an emergency gets a fixed reply: call 111 and tell your supervisor now. Questions about injuries or symptoms are pointed to a person. Questions the approved documents do not answer get “I can’t find this in the approved documents for your site; ask your supervisor”, never a best guess. This is retrieval over a small, controlled library, the core of most RAG development work.

How the assistant is set up

Inputs

Approved site-specific safety plans, task analyses and method statements, safety data sheets, permit procedures, emergency plans, toolbox talk content, the guidance the business has adopted, and workers’ questions by text or voice.

Systems

The document control system (often SharePoint), a search index tagged by site, trade and version, a chat interface in the app crews already use, a model API, an answer log, and an escalation path to supervisors.

Steps

Ingest approved documents only; tag each by site and expiry; ask which site if unknown; retrieve passages; answer with citations; refuse when nothing relevant is retrieved; log question, answer and sources; review gaps weekly.

Human review

The safety advisor approves every document before it is indexed, reviews a weekly sample of answers, and reads every refused or flagged question. Supervisors make every decision on site.

Outputs

Cited answers, escalations to supervisors, a weekly gap report, and usage by site.

Measures

Share of answers with a valid citation, refusal rate, wrong answers in the weekly sample, and how quickly gaps in documents are closed.

Risks

Superseded documents, answers from another site’s plan, gap-filling from general knowledge, use during an emergency, and misheard voice questions.

Illustrative example: a 120-worker Tāmaki Makaurau civil contractor

Illustrative example, synthetic numbers: nine active sites, 1,400 pages of approved safety documents, and 2,000 questions a month. Each question retrieves about 3,000 tokens of passages and adds 1,300 tokens of instructions and question, with replies of about 250 tokens.

Prices are as listed on 19 October 2026. The review line assumes 215 sampled answers at 2 minutes and 150 refused questions at 3 minutes. Test both models on your own questions before choosing; the cheaper model is often accurate enough for retrieval answers, but the review hours stay the same either way.

HSWA duties the assistant sits inside

• The primary duty stays with the business. Section 36 of the Health and Safety at Work Act 2015 requires a business to ensure, so far as is reasonably practicable, the health and safety of workers, including safe plant and safe systems of work. An assistant is one way of getting information to workers. It is not a control in itself.
• Shared sites. Section 34 requires businesses with the same duty to consult, co-operate and co-ordinate. On a site with a principal contractor and subcontractors, the assistant must answer from the principal’s site plan and say whose procedure applies.
• Notifiable events. Section 56 requires notification to WorkSafe as soon as possible after a business becomes aware of a notifiable event, by the fastest means, and section 57 requires records to be kept for at least 5 years. WorkSafe asks for a call on 0800 030 040 immediately after a death. The assistant routes these to people.
• Codes of practice are changing. WorkSafe says the Health and Safety at Work Amendment Act commences on 1 April 2027 and introduces a safe harbour for duty holders who follow an approved code of practice. Expect to re-index guidance when codes are reapproved.
• Privacy. Questions sometimes include injuries or health details. The Privacy Commissioner’s AI guidance applies to the answer log.

A related build: PainPal

Levy Street worked with BetterWorx on PainPal, an AI digital workmate for musculoskeletal pain and injury prevention. Workers describe a task and the discomfort they feel and get practical guidance and next steps. The design lesson carries over: answer from expert-approved content, and hand people to a person when a question goes beyond it.

What supervisors and safety staff keep

Stop-work calls, permits, incident response, deciding whether an event is notifiable, worker consultation, and approving every document the assistant can read.

Where safety assistants go wrong

• Superseded documents. Last year’s method statement stays in the index and contradicts the current one. Index only the controlled folder and delete superseded versions nightly.
• The wrong site. A worker on site B gets site A’s traffic plan. Make the site tag mandatory and ask when it is unknown.
• Filling the silence. When the documents say nothing, a model reaches for a generic figure. Refuse when retrieval finds nothing relevant, and test this deliberately; see RAG retrieval evaluation.
• Noise and numbers. A voice question on a loud site turns “1.5 metres” into “15 metres”. Read back the question and confirm any number before answering.

The other construction workflows we map are tender document extraction and quote preparation from job notes. The construction sector guide explains where each fits.

Written by the Levy Street team in Wellington. Last updated 19 October 2026.