Feature

Hemp high

Green Lifestyle

Ditching its drug rep, hemp’s many applications are touted as an antidote to some of our most eco-intensive products and materials.

hemp-story

The heads of a hemp crop in Tasmania.

 hemp-house-story

A house being built out of hemp bricks.

hemp-food-story

Hemp ice cream contains high levels of vitamins and minerals (including high levels of omega-3 and omega-6), as well as protein and fibre.

hemp-plastic-story

A frisbee made from hemp-based plastics; this material is biodegradable, recyclable, heat and flame resistant, and as strong as regular plastics.

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Think hemp and what immediately springs to mind?

Your brain is probably hovering between images of marijuana and badly-designed leaf print t-shirts.

Yet while marijuana and hemp come from the same plant, cannabis sativa L., they are scientifically different and cultivated in different ways. Marijuana has a high delta-9 tetrahydrocannabinol (THC) content, ranging anywhere from three per cent to a rather high (excuse the pun) 22 per cent. Hemp, on the other hand, has a low THC content that’s typically less than one per cent.

Hemp is one of civilisation’s earliest cultivated crops and has been grown for 6000 years in some regions. Why? It’s a multi-purpose crop that can be used in clothing, skincare products, food, plastic, building materials, paper and fuel. The best bit is hemp boasts substantial eco-points – it’s a fast growing, hardy and high-yield crop that requires little irrigation, herbicides or pesticides. They don’t call it weed for nothing.

“Australia’s climate is suitable for hemp from northern Queensland to Tasmania,” says Ray Rankin from Hemp Gallery. “And although hemp is a temperate climate crop, it can be grown virtually anywhere in the world.”

It is legal to grow industrial hemp in Australia, as in Europe, Canada and New Zealand, but the crop is subject to significant regulation and the laws vary between states and territories.

“In Australia, a hemp licence to grow is issued by the Department of Primary Industries and the grower is required to have the plants checked for the THC component before harvest – the allowable component is one per cent,” says Rankin.

Clothing

Hemp fibre has been used widely throughout history, most notably in the shipping industry. Research shows hemp fibres are longer, stronger, more durable and more lustrous than cotton fibres but the coarse, linen-like texture can irritate the skin – hence ‘canvas’ is derived from ‘cannabis’. Hemp is often blended with cotton, silk and polyester for a softer finish.

Because the cannabis plant grows so quickly, hemp fibres are useful carbon sequesters – where carbon is taken out of the air and put back into the ground. “A primary advantage of hemp over many fibre crops is its potential for high uptake of carbon without requiring use of any herbicides,” says licensed industrial hemp researcher Klara Marosszeky from the Australian Hemp Masonry Company.

Hemp is antimicrobial, mildew-resistant and has excellent UV and absorbent qualities. It’s also a great insulator, which makes it practical in cooler climates. In the fashion stakes, hemp-blend clothing has been the exception but it’s gaining popularity in mainstream circles, particularly though online retailers. Bed linen, lingerie, children’s clothing and accessories made from hemp are also available.

Skincare

Hemp seed oil, derived from the pressing of hemp seeds, helps to maintain skin moisture due to its high concentration of essential fatty acids, which hydrate the skin. It’s especially good for dry or cracked skin and
hugely popular in Australia.

“In Australia, hemp is most commonly grown for seed, which is then pressed for the oil and sold for use in the skincare industry,” says Rankin.

The Body Shop was the first major cosmetics retailer to incorporate hemp seed oil into skincare products. Product manager Valentina Zuban says there was controversy when the hemp range launched in 1998, but it is now the best-selling sub-brand for the company in Australia – and Hemp Hand Protector is the best selling product overall.

“Hemp has the ideal 3:1 ratio of omega-6 to omega-3 essential fatty acids, which is perfect for soothing dry
skin,” says Zuban. “It is also non-pore clogging, making it suitable for all skin types. Hemp seed oil is the perfect skin care elixir and one of the most environmentally friendly crops to harvest, so it really is the perfect ingredient.”

Food

Health-giving hemp seeds contain protein, fibre, vitamins and minerals in addition to omega-3 and omega-6. They are second only to soybeans in complete protein content and contain the best balance of essential fatty acids of any crop plant. Hemp seeds are also rich in gamma linolenic acid (GLA), a rare type of omega-6 that works as an anti-inflammatory.

Hemp foods, including health bars, salad oils, non-soy tofu and raw or roasted seeds, are sold in Europe, Canada and the United States. The Dietitians Association of Australia (DAA) supports the use of hemp seed and hemp seed oil for its nutritional merit.

But – and it’s a huge, game-changing but – it is illegal to use hemp in food in Australia. According to our national regulator, Food Standards Australia New Zealand (FSANZ), “the availability of hemp foods may send a confused message to consumers about the acceptability and safety of illicit cannabis and pose problems for drug enforcement agencies. Therefore, the prohibition on all cannabis species remains.”

Lobby groups, including the DAA, are working to overturn this ban, but progress is slow.

Building materials

It’s possible to live in a house that hemp built. Hempcrete, made from the stalk of the hemp plant, lime and water, is a lightweight and flexible building material that sets like cement. But unlike its eco-intensive counterpart, Hempcrete locks up more carbon than is required to manufacture the bricks or blocks, deeming it carbon-negative. It is energy efficient and a good insulator, plus it promotes clean indoor air and is resistant to mould, insects and fire.

“Hemp masonry or Hempcrete products provide durable, long lasting, thermally and acoustically efficient homes,” says Marosszeky. “They provide excellent air quality as the walls breathe. And as the fibre and carbon-rich walls set or carbonate they draw carbon from the atmosphere.”

Hempcrete is reasonably labour-intensive and as such cost-prohibitive for many owner-builders, and not yet on the radar of most of the larger builders in Australia. But it’s slowly becoming more popular in niche building markets, especially as the push for green housing stock intensifies.

Fuel

The whole hemp stalk can be used to produce various biofuels, such as bio-oil, ethanol, syngas (synthetic gas) and methane. Biodiesel produced from hemp is often called ‘hempoline’.

There is research to suggest that hempoline is a viable alternative to eco-intensive gasoline, but the high production cost, limited supply and low oil yield of hemp fuels make the status quo a lot more appealing to the hip pocket.

Paper

Hemp has been used to make paper for more than 2000 years, but the use of the material has declined in recent decades due to is high processing cost. However, hemp fibres require less treatment for pulp production, and the strength of the fibres makes them ideal for use in high-end paper products where durability is key.

Plastic

Made from the stalk of the hemp plant, hemp-based plastics are biodegradable and recyclable. They’re heat and flame resistant, and as strong as regular plastics.

Hemp plastic has a long history in the automotive industry. Henry Ford used a hemp-blend plastic to build car doors and fenders in 1941, and car makers continue to use hemp in door panels and dashboards because of the material’s durability.

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For more info about hemp, visit: www.hempfoods.com.au and www.hempaustralia.com.au.