Meth Testing Standards NZ (NZS 8510:2017): Inspector's Guide

What is NZS 8510:2017?

NZS 8510:2017 is the New Zealand standard for testing and decontamination of methamphetamine-contaminated properties. Published by Standards New Zealand, it provides a framework for how properties should be tested for meth contamination, what guideline values apply, and how decontamination should be carried out.

The standard replaced the previous NZS 8510:2014 and introduced a significantly higher guideline value — reflecting updated health risk assessments and international best practice. Understanding this standard is essential for anyone involved in meth testing in New Zealand.

The guideline value: 1.5 µg/100cm²

The most important number in NZS 8510:2017 is the guideline value of 1.5 micrograms per 100 square centimetres (1.5 µg/100cm²). This is the level at which a property is considered contaminated and may require professional decontamination.

This was a significant change from the 2014 version, which set the guideline at 0.5 µg/100cm². The revision was based on a comprehensive review of health evidence by Sir Peter Gluckman (then Chief Science Advisor to the Prime Minister), which concluded that the previous level was unnecessarily conservative and was causing significant economic harm without proportionate health benefits.

What the guideline value means:

• Surfaces testing below 1.5 µg/100cm² are considered acceptable for residential use
• Surfaces testing above 1.5 µg/100cm² indicate contamination that may require decontamination
• The guideline applies to all habitable surfaces — walls, ceilings, floors, and fixtures

Testing methodology

NZS 8510:2017 describes two types of sampling:

Composite sampling

Composite sampling involves taking a single sample from multiple locations within a room or zone. The sample represents the average contamination level across the sampled area. This is the most common approach for screening assessments.

How it works:

1. Identify the area to be sampled (e.g., a bedroom, living room, or kitchen)
2. Take wipe samples from 4-10 locations within the area
3. Combine the wipes into a single composite sample
4. Submit to an accredited laboratory for analysis
5. The result represents the average contamination across all sampled locations

Discrete sampling

Discrete sampling involves taking individual samples from specific locations. This provides more detailed information about contamination distribution and is typically used for:

• Identifying hotspots (areas of highest contamination)
• Post-decontamination verification
• Targeted assessment of specific surfaces or fixtures

How to conduct a meth screening assessment

A standard meth screening assessment follows these steps:

1. Plan the assessment

Before arriving at the property:

• Determine the scope — whole property or specific areas?
• Decide on sampling approach — composite or discrete?
• Prepare sampling materials — wipe kits, labels, chain of custody forms
• Review property information — age, layout, tenancy history

2. Visual assessment

Walk through the property and note any visual indicators of potential contamination:

• Staining on walls, ceilings, or surfaces (particularly yellow-brown discolouration)
• Chemical odours
• Unusual modifications (sealed rooms, improvised ventilation, chemical damage)
• Burn marks or residue on surfaces

Important: Visual indicators alone do not confirm contamination. Many contaminated properties show no visible signs. Testing is always required.

3. Take samples

Following NZS 8510:2017 sampling procedures:

• Wear appropriate PPE (gloves, at minimum)
• Use approved sampling materials (typically 100cm² template and sampling wipes)
• Sample representative surfaces in each room or zone
• Label all samples clearly with location, date, and sample number
• Maintain chain of custody documentation
• Photograph each sample location for your report

4. Laboratory analysis

Submit samples to an IANZ-accredited laboratory for analysis. Results are reported in micrograms per 100 square centimetres (µg/100cm²). Turnaround times vary but typically range from 2-5 working days.

5. Report findings

Your report should document:

• The property details and scope of testing
• The sampling methodology used (composite or discrete)
• Sample locations with photographic evidence
• Laboratory results with reference to the 1.5 µg/100cm² guideline value
• Your assessment of the results — pass or fail for each area
• Recommendations for any areas exceeding the guideline value

Using InspectPro, you can photograph and annotate sample locations during the assessment, then add laboratory results when they're available — creating a complete, professional report with full photographic documentation.

Decontamination requirements

If testing reveals contamination above 1.5 µg/100cm², professional decontamination is typically required. NZS 8510:2017 outlines the decontamination process:

1. Preliminary decontamination plan — based on the level and distribution of contamination
2. Decontamination — conducted by a qualified decontamination contractor
3. Clearance testing — post-decontamination sampling to verify the property meets the guideline value
4. Clearance report — documenting that the property has been successfully decontaminated

Clearance testing must demonstrate that all surfaces are below 1.5 µg/100cm² before the property can be returned to use.

Who needs meth testing?

Meth testing is commonly requested by:

• Landlords — at tenancy changeover or when contamination is suspected
• Property managers — as part of routine property management
• Buyers — as part of pre-purchase due diligence
• Real estate agents — to provide assurance to buyers
• Insurance companies — when assessing claims or policy risk

Common misconceptions

"The old 0.5 µg level was safer"

The revision to 1.5 µg/100cm² was based on rigorous scientific review. The previous level caused unnecessary remediation at enormous cost, without evidence of health benefit. The current level is supported by international evidence and expert review.

"You can tell if a house has been used as a meth lab by looking"

Many contaminated properties show no visible signs. Third-hand contamination from smoking methamphetamine can produce surface levels well above the guideline value without any visible indicators. Testing is the only reliable method.

"DIY test kits are just as good as professional testing"

DIY screening kits can provide a preliminary indication, but they are not a substitute for professional testing with accredited laboratory analysis. Professional testing provides quantified results that can be compared to the guideline value, while DIY kits typically only indicate presence or absence above a threshold.

Building your meth testing business

For building inspectors looking to add meth testing to their services, it represents a significant growth opportunity. The investment in training and equipment is relatively modest, and demand is consistent across the rental market.

Key steps:

• Complete appropriate training in meth sampling procedures
• Establish relationships with IANZ-accredited laboratories
• Invest in quality sampling materials and PPE
• Use professional reporting tools like InspectPro to deliver fast, well-documented reports
• Market your services to property managers, landlords, and real estate agents

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