We wholeheartedly support measures to make buildings warmer, drier, healthier and more energy efficient, and agree with the proposals to look at climate conditions in NZ (zones) in a more nuanced way. We also agree that raising the minimum insulation levels for roof, windows, floors and timber-framed walls will make lightweight construction more energy efficient in regard to heating and cooling. If this proposal was just looking at timber-framed construction, we would support Option 2: Raising minimum insulation values to be comparable to international standards, with some reservations (see under “Energy Efficiency” below).
 
However, we strongly oppose the proposal to remove separate minimum R values for heavy mass walls from the Acceptable Solution H1/AS1, until a fully functional modelling program that can model free running, passive solar designed houses with low-carbon mass materials such as Earth, is readily available, easy and cheap to use. We ask that this part of the proposal be put on hold or earth building be exempt.
 
This proposal would put unnecessary hurdles in the way of some of the most sustainable and healthy building solutions available, or even lock these out. Given the Ministry’s objective to make building warmer, drier, healthier and more energy efficient, we feel this possible outcome should be taken seriously and not treated as collateral damage.
 
We are not saying this light-heartedly: Similar decisions about energy efficiency measures in Australia have led to earth being locked out of sustainable building solutions, despite buildings performing well in terms of thermal comfort, cost, carbon, and health. Many once thriving Victorian earth construction businesses were forced into bankruptcy.
 
Apart from understandably being worried about how the proposed changes will impact the future of our long-standing business, we are primarily concerned about the impending climate crisis, material shortages, and unaffordable housing. Our desire to contribute to solutions to climate change, as well as healthy living, has informed all our professional decisions and actions to date, and is the primary motivator for this submission.
 
We would like to go further and invite legislators to investigate the opportunities that would be missed if earth buildings would be pushed back into being Alternative Solutions (which now seems to be the trajectory, despite Earth Building having been written into the NZ Building Code since 1998 and despite the many examples of well-performing buildings in the country).
 
There is the mention of proposed changes encouraging the building and construction sector to invest in new, more innovative materials; but what if some of the best materials get discouraged? We would love to see bigger manufacturers take up some of this already existing technology, which is open-source and has been adjusted to – and tested in – NZ conditions.
 
 
Energy Efficiency
 
Considering that we are in a climate emergency, and loosely based on the findings of the Building for Climate Change consultations carried out by the Ministry in 2020, we feel it is fair to point out that the way Proposal 1 looks at energy efficiency is too narrow and misses very crucial points.
 
It only addresses operational energy and ignores the embodied energy in building materials.
Embodied carbon however is a very important part of the equation in the near future, if we want to reduce our carbon emissions fast enough to uphold our international agreements and avoid dangerous tipping points and climate chaos.
 


This figure adapted from Jukka Heinonen is taken from European research and development of energy efficient, load-bearing solid earth construction (CobBauge), and explains this well.

Even super energy-efficient construction methods such as PassivHaus often fail to address this point.
 





Closer to home, Andrew Alcorn in his doctoral thesis at Victoria University on 'Global Sustainability and the New Zealand House' found - that adding insulation beyond a certain point makes for worse emissions - even when the grid is only 65% renewable as it was when he did the study. With a grid that is 90% renewable the switchover point for making zero difference to emissions (in an electrically heated building) comes at even lower insulation levels - unless you are using carbon negative insulation like straw or wood fibre.
 
So, there seems to be the requirement to differentiate between Carbon Emissions, and demand on the national electricity grid.
 
The current model assumes that all heating and cooling is done with electricity. It also only looks at heating and cooling (which accounts for around 30% of domestic energy use), and not hot water heating (which also accounts for around 30%). Wouldn’t it make more sense to have a more holistic view of operational energy to include hot water heating and account for carbon neutral heating and cooling (off-grid or grid-tied renewables and wood)?
If the concern is how the electricity grid will cope with demand during forecasted extreme weather due to climate change, doesn’t it make sense to diversify and also promote solutions that are not vulnerable to power outages, rather than assuming the only way to heat/cool a building is to blow hot or cold air around an insulated box?
 
We feel that low-carbon thermal mass is a huge part of this equation, and that passive solar design should be encouraged as much as possible. Earth provides thermal mass that is essential for energy efficiency, with the lowest possible embodied energy. Adding carbon sequestering materials (such as timber, straw, hemp) to the mix, allows to fine-tune performance.
 
Development of Light Adobe
 
The beauty of the load-bearing Adobe technique is its simplicity. The single skin construction method is cost effective, fast, and quick to dry out; it is covered by the NZ Standards; it is suitable for a wide range of soils.
 
When H1 was amended in 2008 and the minimum R-value for heavy construction was raised, we were facing a similar challenge to now. Traditional Adobe, similarly to Rammed Earth, is heavy and has a low R-value (1600kg/m3, R0.6 for 280mm walls). These very heavy wall systems are still successfully used to this day by designers who can model and demonstrate H1 compliance.  Our response however was that we wanted a product that just “ticked the box” and in fact achieved more than minimum requirement for solid construction.
 
The thermal performance of earth walls can be optimised for climate by varying density and wall thickness, to achieve the desired thermal conductivity and thermal lag. The challenge is to retain structural strength while reducing the density of the blocks. Only by retaining the load-bearing capacity of the material is it possible to also keep its simplicity and economic advantage.
Our search for solutions ultimately led us to the development of a load-bearing block with much improved insulation properties, but still some thermal mass behaviour (800kg/m3, R1.4 for 280mm walls or R2.0 for 430mm walls). It consists of earth (unfired, clay-rich sub-soil), cellulose fibre (recycled paper pulp or virgin paper pulp) and wood shavings.
 
These blocks have been independently tested in accordance with the NZ Earth Building Standards, plus in-depth testing was carried out by the School of Engineering of Auckland University, both in the laboratory and on full-scale panels; they have been used in several buildings in climate zone 3 with very satisfactory thermal performance. We feel that buildings of this performance should be an Acceptable Solutions without the need for calculation or modelling.
 
There currently are no simple tools to demonstrate H1 compliance whilst taking into account thermal mass, passive solar design and natural ventilation. Until there is such a tool, removing the effective R-values for thermal mass materials is creating a real disadvantage for this type of construction that in fact should be promoted. It is penalizing people who deeply care about climate change and healthy homes, by imposing unnecessary extra costs and making things more complicated than they need to be.
 
 
Warm, Dry and Healthy Homes
 
The proposal states that investing in better quality buildings will have many health and wellbeing benefits for occupants. Better quality doesn’t just mean better insulated. It means looking at living environments holistically and making sure that

• Health issues associated with cold and damp homes are avoided (mould)
• Thermal comfort is achieved (radiant heat is perceived to be more comfortable to humans than hot air blown around – thermal mass increases thermal comfort)
• Indoor air is of good quality, incl. avoiding airborne irritants and toxins from building materials (Earth is totally non-toxic, zero VOC, deodorising and ionising)

 
Earth controls humidity in buildings better than any other material, and its hygrothermal properties have also positive effects on the heating energy demand, beyond its thermal mass properties. The humidity controlling properties of earth have been extensively researched and documented internationally. It is one of the most remarkable properties of earth. Earth is the most healthy building material we could wish for.
 
According to modelling carried out using the WUFI Plus software, even small changes in materials have an influence on relative humidity and heating demand. Using earthen materials, exposed timber, and natural paints (rather than Gipsum Board and acrylic paint) created drier and warmer (and thus healthier) conditions.
Coincidentally, these materials also have better environmental performance and lower embodied carbon.
 
 
Building for Climate Change
 
There were some key themes identified in the consultation on Building for Climate Change carried out last year that should inform the suggested proposals for changes to the Building Code. At the very least, the suggested proposal should not work against points raised.
It just happens that the earth building materials and construction methods we work with – and into which we have invested years of R&D to respond to legitimate concerns around energy efficiency – perform really well in most of these points.

• Better information about low carbon building

This is what we are trying to achieve with this submission. Why not aim for carbon neutrality or carbon sequestring buildings? Some very good information can also be found on Builders for Climate Action.

• Cost

Earth walls are comparable in cost to other types of good quality construction; scaling production of earthbuilding materials might reduce costs. With the cost of all building materials increasing since Covid, it seems a wise idea to look for building products that can be produces from local raw materials, that often are by-products of other processes.
Having to model these buildings would add cost.

• Raw materials, waste and re-using materials

Unstabilized earth and added natural fibres are abundant local resources, zero waste and fully recyclable.

• Building strength and resilience AND low carbon

Modern earth buildings performed very well in the earthquakes and further full-scale EQ testing of various techniques was carried out by Auckland University.

• Consenting shouldn’t be hard

The 1998 NZ Earth Building Standards are well established. They have recently been revised and expanded after a huge industry and volunteer effort and public consultation.
Not having the 2020 revised standards cited and potentially having to thermally model these buildings moving forward would make consenting more difficult.

• Action to reduce CO2 emissions (people want operational efficiency and 87% agree whole of life embodied carbon should be included)

For earthen materials these calculations are not complicated, and the results are very favourable.

• Keep things simple

Single skin, load-bearing Adobe is so simple that it can be carried out by owner-builders with little training. We have worked with both interested block layers and carpenters and they all comment how straightforward and enjoyable this way of building is.
We sometimes wonder if its simplicity is one of the reasons why it is being overlooked. Surely solutions to some of the most pressing problems we face can’t be THAT simple.
 
Considering we are in a climate emergency, whatever option is selected, we at least need exemptions for lower density earth buildings and accounting for embodied energy (or carbon sequestration) in the Building Code.

My mission today on Natalie Sisson's 10 Day Freedom Plan Blog Challenge (should I accept it) is to unlock my Superpowers! Nothing short of that...
It is those things that I am good at and love doing and that come naturally to me. Perhaps because they come naturally, they might not seem like something special, but today is the day to really think about them and celebrate them. 

I have decided to share a couple of videos that show me in my power. They were a revelation to me when I first watched them, and helped me overcome self-consciousness and really see myself from an outside perspective.

I am not a person that solely identifies through work, but since I am in the happy position to be very passionate about my work, I definitely think that Earthbuilding is one of my Superpowers! 

I love organizing and project managing, without having to be the official "face" of a campaign or event. I see the big picture and have a lot of attention to detail, like working in a team or by myself, and love when things come together. The biggest event I have helped organize so far has been the International Straw Building Conference and the Climate Voter Debate.

From an early age I have been an activist. I believe in the power of peaceful protest and civil disobedience. I feel that urgent action on Climate Change not only is essential to preserve our existence, but could lead to a shift in how we live together on this planet. I see the crisis as huge potential for positive change. Care for the environment and people is what motivates me in everything I do, but I also feel empowered by putting my body on the line for the things I believe are important. Read more about my WHY.

Want to build something?

Well, I might be biased, but being trained in design, I would suggest that regardless of whether you legally need to or not (ie even if your project is smaller than 10m2) you get some plans drawn up. It really helps being able to visualize something, down to all the details. If your project is small, you can do the working drawings yourself, for example using a program like Google Sketchup. If your project is more elaborate, I would advise that you get really clear on your "vision" and then write up a brief for a professional designer who has experience in the (natural) building technique of your choice.

Personally, it has taken me some years to understand that it is helpful to engage professionals to help me with things that are beyond my expertise or to help me develop myself professionally. I am very much a DIY kind of person and a perfectionist on top of that, so you can imagine that I have not always done things the easy  way. My motivation for doing things without (professional) help was partially aimed at saving costs, an equation that didn't always add up, and partially aimed at the sense of achievement of having it done "all by myself".

My business is one of my bigger works in progress. It started out with me buying an existing mud brick production set-up and then visualizing all the services I wanted to offer. I was very inspired by it all and my ideas were very vivid, so I boldly put them out there on my very first website in 2002. I had been building in Earth for around 10 years by then, so I had the technical confidence, but would people actually engage me? I was blown away when a couple of years later, everything I said I could do I had done! The "mud stuff" was the easy part for me, learning to run a business and operating in the building industry however was a steep learning curve and something that I witnessed trip up quite a few people who were working in my field. We love being creative, but do we equally enjoy building and nurturing our businesses?

Especially when it comes to running my business, I have been blown away by the difference professional support can make.  Locally, I have worked with the extremely inspiring Johny O'Donnell from ShiftOn Motueka and I am also working with Natalie Sisson from the Suitcase Entrepreneur.

Today we are on day three of her 10 day blog challenge and she has asked me to talk to you about my vision for the future, or how she puts it: My "Perfect Day".

I would like to start by sharing that I have experienced a bit of shift inside of my self in the past two years, to a place where I feel deep gratitude for my life. Gratitude has changed everything. It makes me focus on the little things that make my day, the lessons in all the experiences, the growth that comes from challenges. However, it doesn't make me want to stop moving and challenging myself. I am content with my life, but I can identify many areas that need improvement, or maybe I should rather call it balancing.

For example, the work-life-play balance. It is something most of us struggle with. In my perfect world I would not make a differentiation between the three things, but the reality is that I often work really hard making bricks, building something or organizing a workshop, and then don't spend enough quality time with my loved ones or doing the things that sustain me, like yoga and solo time in nature.

It is really hard to actually describe a possible "Perfect Day", but for the sake of visualizing it the way I would visualize a building if I want to make a plan and make things happen, here is my first draft:

"I wake up to the dawn chorus I love so much, the sky is a feint pink and blue. I open the window next to my bed and quietly lie there a little while, drinking in the fresh morning air. I have an hour to myself before the others get up. I cherish the silence and try to recall my night dreams, before getting up and drinking a glass of lemon water. I do my yoga, and this centres me and sets me up for the day, leaving me warmed up and supple. My head is not spinning from the many things on my to-do-list, as I have written them down the night before and identified my three main priorities for the day. This focuses me and makes me feel relaxed. 

I have breakfast with my partner Scott. He cooks yummy eggs with leek and mushrooms. We sit in the morning sun outside, in our abundant teeming garden. The bees are buzzing between the flowers and we can pick fresh cherry tomatoes and some basil to go with our home grown eggs. 

Today we are shooting video footage for my online course on "DIY interior Earthen Features". Scott is behind the camera, which makes me feel relaxed and able to let my passion for earth shine through, without being too self-conscious. I think of how I can inspire people to create wonderful healthy interiors using natural materials. I think how satisfying it will be to have people share photos of their work with me one day and know that I could contribute to their success by sharing my experience in a visually engaging way.

We are happy doing creative work and spending time together until mid afternoon. Then I do a couple of hours of concentrated solo work in the office, fleshing out my next natural building course which will be held on a client's property. I enjoy customizing solutions for people and working with the materials on site. 

Late afternoon I take our dog for a walk at the beach nearby. The rocks, driftwood and waves never cease to inspire me. I think of a piece of land art I want to do and then about our upcoming three month trip to South America. I want to catch up with my earthbuilding friend from Chile and check out all the amazing things she has spoken about. I am excited about it all and feel very lucky to be able to go on this adventure."

This exercise is fun, but it is hard to write up publicly. How often do we dare to share with others our ideas for a perfect day? What would be your perfect day? What does it smell like, look like, feel like, sound like? 

As a young adult I heard a lot of "It ain't possible". It was really getting to me. If you are ever talking to someone starting to figure out what to do with their lives, please don't use that sentence!

Wanting more freedom in my life has been one of the major drivers why I emigrated to New Zealand and started my earthbuilding business in 2002. The Kiwi "can-do" attitude and pioneering spirit inspires me to this day.

Reflecting on what freedom meant to me back then and what moved me to change my life quite drastically and take a leap of faith:

• I wanted to be free to structure my days around the needs of my children and be able to take time off if they ever got sick - without fear of losing my job (ie no day care, commute or rigid 9-5 job)
• I wanted the freedom to adjust the intensity of my work effort to the needs of my body
• I wanted the freedom to chose whom to work with
• I wanted to be free from stereotypes of what a woman/mother my age is capable of or should be doing
• I wanted freedom from the inner critic who was trying to tell me I couldn't do certain things because I wasn't practical or talented enough
• I wanted to be free to dream and try things for myself

So, distilling is down, freedom to me is about being able to live a self-determined life, to create with my own hands, and to do the things that matter. Having my own business has given me this kind of freedom but it has also been a ton of hard work, I won't deny it. 

This is the core of my WHY. How this fleshes out for me 14 years into business is slightly different to the reasons I used to have when I started out. My babies have grown into wonderful young adults and I no longer need to prove myself anything. Freedom to me now has much more to do with being able to grow as a person and making a positive contribution in the world.

• I love inspiring people through my work and simple, sustainable lifestyle
• I love empowering people to be creative and shape their own healthy living environments
• I love learning new skills
• I love diversity
• I love stretching beyond my comfort zone
• I love a job well done
• I love simple, natural solutions 
• I love contributing towards peace and healing
• I love to restore and regenerate
• I love courage

and the list could go on, but I am sure you get the (a bit cheesy) picture!

Freedom for me now simply is being able to do these things I love, because I know that my light shines the brightest when I am filled with love and this is when I touch people's lives.  And at this point in my life, I need to nourish the love by going out into the world more.

It is nice to share my WHY with you. Getting clear on the WHY feels very motivating and gives me clarity of where I am headed. It is the Southern Cross in my firmament. 

Do you know your WHY? You can zoom in on it by thinking about what your contribution is to the world/the lives of others when you are at your personal best and what the impact of your contribution is at that time. If you feel like sharing, leave a message below. Thank you.

This blog post is in response to Natalie’s 10 Day Freedom Plan Blog Challenge Day 2

Since I  first picked up a lump of clay to build a house with 25 years ago, natural building has come such a long way!
​Back then, learning opportunities were far and wide and people were telling me to "get a real job", rather than "play in the mud". But I have stuck with it, because my relationship with Earth as a building material has been one of love at first sight and has grown into a deep passion over the years. I am so grateful to my teachers, among them Prof. Gernot Minke, and to all the learning opportunities I have had through all the wonderful building projects I have been part of up to now.

Today I feel I have grown into a place of deep knowledge and sound experience with the material. I am thrilled to see earth building become more and more popular all across the globe, uncountable people working towards a tipping point where we can collectively re-claim our ability to build healthy living environments for ourselves, using local materials, strengthening our communities and our own sense of self-determination.

This is really the very first thing that came up for me. I know that I need to balance my desire for beauty and quality with common sense and just taking action. Perfectionism can be a huge force for good, but it can also paralyze me into procrastination or inaction. I found some very valuable information and resources on how to deal with perfectionism on The Happy Sensitive blog. 

Working with Earth in itself is a great teacher for this challenge. There is a sweet spot where your energy expenditure is balanced with the result - where things are "good enough". 
This is something I focus on when coaching others to work with earth, because I want the experience to be positive for them, not just a lot of hard work. I help clients streamline processes, refine their technique, make use of the best tools and save on costs. Why then is it so hard for me to apply the same principles when it comes to taking steps towards making my new dreams a reality?

So, I guess this is the first nugget of wisdom that I am picking up in this process:

It will be more important to take consistent small steps in the right direction than to try and get everything lined up perfectly before launching a new endeavour.

​​Yes, I do have a very busy life. Don't we all. Personally, I juggle running my business, making a living, family life and the many things that need doing on our land (growing food, a reforestation project, chickens, building, etc.) along with hosting people interested in learning about Earthbuilding at our place. There is never a dull moment and the to-do-list is never-ending.

However, as Natalie Sisson very rightly asks us to consider on the first day of our blog challenge is what we prioritize over and above the things we dream of achieving. This will no doubt be a work in progress as long as I live, but the first step in the right direction is to really get clear on what is important to me at this point in my life. As I move from being a mother of school children to supporting my children through tertiary education, the focus will no doubt shift. 

I want to create a diverse income stream that enables me to travel and direct my energy at projects that serve communities or the regeneration of natural ecosystems. I want to expand my horizon and get inspired, in order to instill creative richness and international best practice into my work here in New Zealand. In order to achieve this, I need to make the time and space to put systems in place that allow me to leave home for a while.

Sounds simple? I don't think so. But I should remember the youthful can-do attitude I had when I emigrated and started my business. It took me a couple of attempts, but I got there in the end. On that note I leave you for today with one of my favourite quotes:

Thank you for making it this far! If you feel like sharing what your dreams are, drop me a line below. By verbalizing our dreams we weave the magic to make them happen... 

Being built from local silty soil on a slightly raised site in the middle of a coastal swamp area, without any foundations, the walls have been affected by salty dampness. This resulted in continuous damage to the base of the earthen walls, the absorbed salts causing the surface to blow out, both on the interior and the exterior of the building.

​In 1960 the Marlborough Historical Society and Historic Places Trust started the first major restoration, using techniques that at the time were considered best practice. The deteriorating material at the base of the walls was replaced with two to three courses of concrete blocks, and the whole cottage was re-plastered with a cement stabilized earth render. Unfortunately no damp proof membrane was installed at the time and so the root cause of the damage was not mitigated, but the repairs certainly strengthened the building and were crucial for its survival to this day. However, it was apparent that the building was in dire need of love and that there was still salt damp damage affecting all surfaces. Solid Earth Ltd from Nelson were contracted to carry out structural repair work and give the cottage a total makeover, working to the guidelines of historic places trust and under the supervision of structural engineer Gary Hodder of Nelson.

Why are our homes damp?
A home - even a modern one - can be damp for many reasons:

• Very obvious scenarios would include water damage from leaky plumbing or flooding, but in most cases the cause is more hidden. 
• Poor house design can lead to water slowly leaking in over a prolonged period of time, often in hard to get to places such as the ceiling or the framing around windows and doors; 
• Poor insulation can lead to cold spots within the construction where condensation can form unnoticed; 
  
• The use of building materials that don't regulate humidity or trap moisture, such as drywall painted with acrylics;  
• Poor ventilation can lead to substantial condensation of moisture introduced to the home by its occupants, especially in kitchens, laundries and bathrooms.
• and while increasing the air tightness of buildings helps with energy efficiency, it exacerbates the problem arising from poor ventilation.
  

Indoor air quality
Many factors influence indoor air quality (IAQ), including gases, particulates, and in this case microbial contaminants. Controlling indoor air humidity plays a vital role in creating a healthy home. The recommended "Comfort Zone" for relative humidity in the home is 40-60% RH. Deviations from this range can coincide with increased levels of bacteria, viruses, mould and other factors that reduce air quality and lead to health problems. Some indoor air quality specialists recommend that relative humidity be maintained at less than 55% to control fungal proliferation.

What are the possible health effects of exposure to mould?
The fungal spores produced by common mould species are linked to some serious illnesses. A damp home doesn't only increase your risk of developing a respiratory illness such as asthma, it can actually cause a biotoxin related illness called Chronic Inflammatory Response Syndrome. 

People often report a cluster of nasty symptoms, such as 

• fatigue 
• headaches,
• joint pains 
• weakness
• abdominal pain
• decreased brain function
• extreme mood swings
• depression
• and a weakened immune system, just to name the main ones. 

Mycotoxins can cause adverse health effects at very low concentrations. Some of the moulds that are known to produce mycotoxins are commonly found in moisture damaged building materials. Exposure pathways include inhalation, ingestion and skin contact. 

28% of people have a genetically influenced innate immune response that gets turned on by environmental mold, but it doesn’t turn off. If you’re one of these people, if you get exposed, you get sick, and you won't get better until the problem is remedied. 

A lot of good advice on how to prevent moisture build-up in homes and how to remedy mould problems can be found online, so if you need specific advice I encourage you to do some research, based on your individual situation. In a nutshell however, creating healthy, dry living conditions for you and your family is based on your behaviour, as well as the design and material choices of your home. 


Develop good habits

Make ventilation part of your daily routine
The simplest and cheapest way to ventilate is to open doors and windows regularly to allow fresh air from outside into your home.
In winter, cross-ventilate your house at least once a day for a few minutes with wide open doors and windows. To avoid condensation problems, do this when you turn off the heating - for example, before you leave the house in the morning and just before you go to bed at night.

Sort out your bathroom, kitchen and laundry ventilation
The most significant sources of moisture in your home are the kitchen, bathroom and laundry. 
Consider fitting extractor fans in all these rooms (placed as close to the moisture source as possible).  Make sure they vent to the outside, not into the roof space. Because extractor fans remove moist air but don't bring in fresh air to replace it, you'll need some other way of getting fresh air into the room. 
Alternatively get into the habit of opening a window after you have taken a shower or when you cook.

Fix any leaks
This might sound obvious... but if you suspect ongoing water damage, get to the root of the problem. Sort out leaky plumbing, inadequate flashings, blocked down pipes and so on.

Avoid using unflued gas heaters 
They release large amounts of moisture and toxic combustion gases into your house. 

Keep furniture away from external walls
Leave a gap of 100mm or more behind large objects like furniture and keep mattresses off cold floors to enable air to circulate.

Look for mould regularly and remove it if you find any 
Regularly check for signs of mould in your home. Places to look out for are windows, bathroom tiles and behind furniture and paintings. If you find any mould, clean it off using a natural fungicide such as borax, vinegar, baking soda or hydrogen peroxide.