In recent years, methamphetamine contamination has emerged as a major issue for property owners, tenants, and property managers throughout New Zealand. With meth use and clandestine labs producing long-lasting contamination, many are wondering: how long does meth residue really last in a house?
The solution is simple — meth residue does not dissipate by itself. If not properly cleaned, it can last in a home for years and even endanger occupants. The issue is usually imperceptible and difficult to spot without proper analysis.
What Exactly Is Meth Residue?
Methamphetamine, whether burned or cooked at home, gives off a combination of poisons that stick to household surfaces. Such residues need not be apparent. They tend to settle upon walls, ceilings, rugs, drapes, furnishings, kitchen cabinetry, and even in the interiors of air ducts or in light switch boxes.
This residual contamination is also known as meth residue, meth contamination, or third-hand meth exposure. It does not have a persistent odor and is not visible to the naked eye. You may be residing in a clean-looking house, but still have contamination levels high enough to be of health concern.
How Long Does the Residue Last?
In contrast to dust or smoke from cigarette smoke that clears naturally with time or ventilation, meth contamination is sticky and chemically resistant. It adheres to porous materials like plasterboard, timber frames, insulation, soft furniture, and even plastics. It won’t dissolve or naturally decompose once it’s embedded. In a few instances, residue has been found ten or more years after meth had last been used in a house.
Superficial cleaning or painting over surfaces will not remove the contamination. In fact, painting can sometimes seal the residue underneath, making it even more difficult to remove later.
Why Is It So Difficult to Remove?
Methamphetamine is produced with a combination of potent, toxic chemicals. When used or cooked indoors, those chemicals don’t simply evaporate. They adhere to surfaces and seep deep into materials.
Residue can end up in ventilation ducts, air filters, insulation, curtains, mattresses, and children’s toys. Because meth is greasy and chemically active, regular household cleaning products can spread it around rather than remove it.
What Are the Health Risks?
The symptoms of living in a contaminated house depend on the amount of residue, how long people are exposed, and the health of the individuals. In low-contamination houses, some people experience constant fatigue, skin irritation, or difficulty sleeping. In houses with more contamination — particularly those that were used as meth labs — symptoms can be worse.
Medical problems can include:
- Headaches
- Eye and throat irritation
- Respiratory issues like asthma or coughing
- Skin rashes
- Changes in mood or behavioral changes in children
- Difficulty concentrating or sleeping
- Nausea or fatigue
Children are especially at risk because they are smaller, have weaker immune systems, and often engage in hand-to-mouth behavior. Crawling babies on dirty carpets can be exposed to higher levels of residue than adults on a couch.
Can a House Be Tested for Meth?
Yes, and it’s strongly advisable in some cases, like when purchasing a property, taking occupancy of a rental, or in the event of suspected prior drug use. One rule of thumb is to test whether the price appears suspiciously low or if the property has been empty for an extended period.
Testing Methods:
1. DIY Meth Test Kits
You can purchase test kits online or at some hardware stores. They provide a rapid, general indication but are not as accurate as professional testing. DIY kits don’t quantify how much meth is present, only if it may be present.
2. Professional Surface Testing
This is the most accurate way to find out if a home is contaminated. Technicians collect surface samples from multiple areas and send them to a laboratory. Results show contamination levels in micrograms per 100 cm². In New Zealand, the current recommended safe limit is 1.5 micrograms, although this varies slightly by region and context.
Can Meth Be Cleaned Out of a House?
Yes, but it demands more than a mop and bucket. Proper decontamination requires specialist cleaning techniques, personal protective equipment, and in certain cases, removal of materials such as plasterboard, carpet, or insulation.
The Decontamination Process Typically Encompasses:
1. Site Assessment
A professional assesses the extent to which the contamination has penetrated. This ranges from walls, ceilings, and flooring to ventilation and soft furnishings.
2. Thorough Cleaning
Approved cleaning agents are used to treat all affected surfaces. This often includes scrubbing walls, removing residues from ventilation systems, and deep cleaning cabinetry and fittings.
3. Material Removal (if needed)
If meth has soaked into materials like carpets, insulation, or even plasterboard, these may need to be removed and replaced.
4. Clearance Testing
After cleaning, the property is tested again to make sure residue levels are within safe limits.
What About Low-Level Contamination?
In some homes, the contamination is caused by recreational use of methamphetamine rather than full-scale production. Cases may not need a full strip-out but still require professional attention. Even low levels of residue can exceed health standards and impact vulnerable individuals.
Just because there’s no visible harm or noticeable smell doesn’t mean the house is safe.
Who Covers the Cost of Decontamination?
The cost usually lies with the property owner. For landlords, it is your responsibility to ensure that the rental property is safe and habitable. New Zealand’s Tenancy Services requires that landlords deliver houses free of harmful contamination. If tenants are the ones who used the meth and you have insurance, you can possibly recover some of the cost — but this is policy-dependent.
How Much is Meth Cleaning?
Prices will differ depending on the size of the home and the extent of contamination.
- Basic surface sampling: NZD $250-$500
- Light clean: NZD $2,000-$10,000
- Full remediation including replacement of materials: NZD $10,000-$50,000 or more
Remember that by not treating contamination, you will incur even more expense down the road — like legal problems, lost rent, or a dent in your image as a landlord.
Can You Smell Meth Residue
Normally, no. Meth contamination doesn’t have a sure smell. A few people have reported a very slight chemical or ammonia odor, but for most, there is no smell at all. A house could be newly painted and well-maintained, yet contain hazardous levels of contamination underneath.
What To Do If You Suspect Contamination
If you suspect a house has been contaminated with meth, do the following:
- Inquire of the real estate agent or property manager about the history of the home
- Schedule professional meth testing by a certified provider
- Do not attempt to clean it yourself. Amateur efforts can distribute contamination further
- If the test is positive, seek guidance from a licensed decontamination professional.l
Final Word
Meth residue is not something that will disappear over time. It can remain hidden in a house for decades if not removed professionally. It won’t wash away with regular cleaners, and it can’t be painted over or ignored.
Whatever you are, whether a buyer, tenant, landlord, or property manager, there are risks to be aware of, as well as your liabilities. If in doubt about the history of a property, test it. That small initial cost may save you thousands down the line and even safeguard your own health or the health of your tenants.
Taking precautions is not panicking. It is mere common sense.
