Your True Standard kit starts with 80+ analytes.

Lead is like an invisible poison that can sneak into your water from old pipes, just like rust but much more dangerous. It's especially harmful to kids because it can affect how their brains develop, making it harder to learn and pay attention in school. Even tiny amounts can cause problems, so it's important to test your water regularly.

Arsenic is a natural element that can dissolve into groundwater, kind of like sugar dissolving in tea. It comes from rocks and soil underground. Even though you can't see, taste, or smell it, drinking water with arsenic over time is like slowly poisoning yourself. It's especially common in well water.

Mercury is a shiny, silver liquid metal that was used in old thermometers and some light bulbs. It's like a toxic quicksilver that can damage your brain and nervous system. When it gets into water from coal plants or factories, bacteria turn it into methylmercury, which builds up in fish - that's why pregnant women are warned about eating too much tuna. Even tiny amounts can affect how kids' brains develop.

Cadmium is a toxic metal that can leak into water from old pipes, batteries, and industrial waste. Think of it like lead's sneaky cousin - it's not as famous, but it's just as dangerous! It loves to build up in your kidneys over time, like rust accumulating in a pipe. Smokers get extra cadmium exposure because tobacco plants absorb it from soil. It can stay in your body for decades.

Chromium exists in different forms - chromium-3 is actually a nutrient your body needs in tiny amounts, but chromium-6 is a dangerous carcinogen made famous by the movie 'Erin Brockovich.' It's like having two twins where one is helpful and one is harmful. Chromium-6 can get into drinking water from metal plating factories, leather tanning, and old industrial sites. It can cause cancer if you're exposed to too much over time.

Copper is a reddish-brown metal used in water pipes. In small amounts, it's actually good for you - your body needs it! But when pipes corrode, especially in acidic water, too much copper can dissolve into your drinking water. It's like seasoning food - a pinch is good, but a whole spoonful will make you sick. You might notice a metallic taste or blue-green stains in your sink when copper levels are high.

PFOA is called a 'forever chemical' because it's like the Energizer bunny - it just keeps going and going and never breaks down in nature! It was used to make non-stick pans and waterproof jackets, but scientists discovered it can stay in our bodies and the environment for decades. Think of it like permanent marker on your skin - it's really hard to wash off.

PFOS is PFOA's cousin - another forever chemical that was used in firefighting foam and stain-resistant sprays. Imagine spraying your couch to make it stain-proof, but that chemical never goes away and can end up in your drinking water. It builds up in fish, animals, and even in our blood over time.

PFHxS is another member of the forever chemical family that was widely used in chrome plating, firefighting foam, and stain-resistant coatings. Think of it like PFOS's smaller sibling - it has a shorter chemical chain but still sticks around forever. It can travel through groundwater and contaminate wells miles away from where it was used, like an invisible traveler that never stops moving.

PFBS was created as a 'safer' replacement for PFOS, but it's still a forever chemical that doesn't break down. It's like replacing one type of permanent marker with another - it might be slightly less toxic, but it still never washes off! Industries started using it thinking it would be better, but scientists are finding it still builds up in water and our bodies.

PFNA is a forever chemical that was used in non-stick cookware, food packaging, and carpet treatments. What makes it especially sneaky is that it builds up in your body over time - it's like filling a piggy bank that you can never empty. The longer the chemical chain, the more it tends to stick around, and PFNA has a pretty long chain. It's been found in the blood of almost all Americans.

PFHxA is a shorter forever chemical that companies started using to replace the longer ones like PFOA. The problem is, shorter doesn't mean safer - it actually moves through water even faster! Imagine trying to catch a small, slippery fish versus a big slow one - the small one is harder to filter out. That's PFHxA in drinking water treatment plants.

GenX was created by chemical companies as a replacement for PFOA after PFOA was found to be dangerous. It's like when a company recalls a toy and sells you a 'new and improved' version - except this one might have its own problems! GenX became famous when it was discovered in drinking water near a manufacturing plant in North Carolina. It's still a forever chemical that doesn't break down naturally.

PFDA is one of the longer forever chemicals, which means it really likes to stick around in your body and build up over time. Think of it like glue that gets stronger the more layers you add. Because it's so long, it's especially good at accumulating in your liver and blood. It was used in non-stick coatings and fire-resistant materials but is now being phased out as we learn more about the risks.

E. coli is a bacteria that lives in the intestines of humans and animals. Finding it in your water is like discovering someone's poop got mixed in - super gross and dangerous! It means sewage or animal waste has contaminated your water. While most E. coli won't make you super sick, some types can cause serious stomach problems.

Nitrate is a chemical from fertilizers that farmers use to help plants grow bigger. When it rains, this fertilizer can wash into wells and groundwater, just like food coloring spreading in water. It's especially dangerous for babies under 6 months because it can stop their blood from carrying oxygen properly - imagine trying to breathe through a straw that keeps getting smaller.

Chlorine is added to city water on purpose, just like adding chlorine to swimming pools to kill germs and bacteria. It keeps the water safe as it travels through pipes to your house. You might notice a slight pool smell or taste - that's the chlorine doing its job! Too little means germs might survive, but too much can taste bad and irritate your skin.

When chlorine (added to clean water) mixes with natural stuff like dead leaves and dirt in water, it creates new chemicals called trihalomethanes. It's like when you mix baking soda and vinegar - you get something totally new! These new chemicals can be harmful if you're exposed to them for many years.

Hard water has lots of dissolved minerals like calcium and magnesium - imagine trying to dissolve a whole bunch of chalk in your water! These minerals make it hard for soap to create bubbles and leave white spots on dishes. It's not dangerous to drink, but it can clog your pipes over time and make your water heater work less efficiently.

pH is like a thermometer for how acidic or basic your water is. The scale goes from 0 to 14, with 7 being perfectly neutral (like pure water). Numbers below 7 are acidic (like lemon juice or soda), and numbers above 7 are basic (like baking soda). Water that's too acidic can eat away at your pipes like acid eating metal, releasing other metals into your water.

Ever notice that 'new furniture smell'? That's often formaldehyde, a chemical that comes from pressed wood products like particle board. Imagine if your desk or bookshelf was slowly releasing invisible gas into the air - that's what formaldehyde does! Breathing it in can make your eyes water, give you headaches, and make it hard to breathe, kind of like when you chop onions but all the time.

PM2.5 particles are so tiny that 30 of them lined up would be as thin as one human hair! They're like invisible ninja dust that's small enough to sneak deep into your lungs when you breathe. Unlike regular dust you can see, these particles are so small they can get all the way into your bloodstream, just like how a tiny splinter can work its way under your skin.

Carbon monoxide is called 'the silent killer' because you can't see it, smell it, or taste it - but it's super dangerous! It's created when things burn without enough oxygen, like a car running in a closed garage or a broken furnace. When you breathe it in, it tricks your blood cells into carrying CO instead of oxygen, like accidentally drinking poison instead of water.

VOCs are chemicals that evaporate easily at room temperature - think about how you can smell fresh paint or nail polish remover from across the room. That smell IS the chemicals floating through the air into your nose! Common VOCs include things from paint, cleaning products, air fresheners, and new furniture. While some are harmless, others can make you sick. Total VOC testing measures all of them combined.

Benzene is one of the most dangerous VOCs because it causes cancer, even at low levels. It's a major component of gasoline and cigarette smoke. When someone smokes indoors or when you have an attached garage, benzene can build up in your home. It's sweet-smelling but super toxic - imagine breathing invisible poison that damages your bone marrow and blood cells. It's part of a group called BTEX, the four most important VOCs to test for.

Toluene smells like paint thinner because it IS paint thinner! It's used in paints, nail polish, adhesives, and many household products. When you paint a room or use super glue, that strong smell is mostly toluene evaporating into the air. Short-term exposure gives you headaches and makes you dizzy - it's like your brain is getting foggy. Long-term exposure can affect your nervous system and kidneys.

Ethylbenzene is a chemical used to make styrene (for plastics) and is found in gasoline, paints, and varnishes. It's the 'E' in BTEX testing. You can smell it at low levels - it has a sweet, gasoline-like odor. When you smell fresh paint or walk through a parking garage, you're probably breathing ethylbenzene. It can irritate your eyes and throat, and long-term exposure might increase cancer risk.

Xylene is actually three similar chemicals (o-xylene, m-xylene, p-xylene) usually found together, like three siblings who always hang out. It's used in paints, permanent markers, paint thinners, and adhesives. That sharp, sweet smell when you use a Sharpie marker? That's xylene! It can make you feel dizzy and confused, kind of like being drunk, because it affects your brain temporarily.

Styrene is the building block for polystyrene - the plastic used in foam cups, packing peanuts, and insulation. When you open a new foam cooler or walk into a boat repair shop (fiberglass), that distinctive sweet smell is styrene. It evaporates from foam products, especially when new or heated. Breathing it makes you tired and gives you headaches, and it might cause cancer with long-term exposure.

TCE is a powerful degreasing chemical that was widely used in factories and dry cleaners. Even though it's mostly banned now, it contaminated soil and groundwater near industrial sites. It can seep up through basement floors in a process called vapor intrusion - like invisible toxic gas sneaking into your home from underground. It's a known carcinogen that can cause cancer even at low levels.

PCE is the main chemical used in dry cleaning - that distinctive 'dry cleaner smell' on your freshly cleaned clothes is PCE evaporating. It's also used as a degreaser. Homes near dry cleaners or above contaminated sites can have PCE vapor intrusion. Like TCE, it's a carcinogen that can enter homes through basement cracks. Even bringing dry-cleaned clothes home releases PCE into your indoor air for days.

Acetone is one of the most common VOCs in homes. It's the main ingredient in nail polish remover and paint thinner. Your body even makes small amounts naturally! That fruity, nail salon smell is acetone. While it's less toxic than many VOCs, high levels can still irritate your nose and throat and make you feel lightheaded. Good news is it evaporates and leaves your body quickly.

MEK is a powerful solvent used in super-strong adhesives, paint removers, and coatings. It has a sharp, sweet smell like acetone but stronger. It's commonly released during home renovations when using adhesives for flooring or countertops. Breathing MEK is like acetone on steroids - it can make you dizzy, nauseous, and give you headaches much faster. It also irritates your eyes and respiratory system.

Limonene is what makes oranges smell like oranges! It's extracted from citrus peels and used in tons of cleaning products, air fresheners, and personal care items. Many 'natural' or 'green' cleaners are loaded with limonene. While it seems harmless, it can react with ozone in the air to create formaldehyde and tiny particles. It's one of the most common indoor VOCs, especially in homes that use lots of scented products.

Alpha-pinene gives pine trees and pine-scented products their characteristic smell. It naturally comes from wood, especially pine and other conifers, but it's also added to cleaning products and air fresheners. New wood furniture and pine floors release it. Like limonene, it can react with ozone to form irritating particles. It's very common in homes and generally considered low toxicity, but can trigger allergies in some people.

Acetaldehyde is a toxic VOC that comes from burning things (like candles, incense, and cigarettes) and also off-gases from building materials and furniture. It's what gives partly-burned materials that distinctive acrid smell. Your body also makes it when breaking down alcohol - it's what causes hangovers! It's a probable carcinogen and can irritate your respiratory system. It's especially high in homes with smokers or lots of candle use.

Hexanal is one of the most common aldehydes found indoors. It comes from cooking (especially with vegetable oils), building materials, and the natural breakdown of fatty substances. That slightly grassy, fatty smell in your kitchen after cooking is partly hexanal. While it's not as toxic as formaldehyde, it can still irritate your eyes, nose, and throat. It's a good indicator of indoor air quality - high levels mean poor ventilation or lots of cooking emissions.

Nonanal is another very common indoor aldehyde with a fatty, citrus-like smell. It comes from cleaning products, personal care items, building materials, and cooking. It's often added to fragrances and cleaners for its pleasant scent, but it also forms naturally when materials age. Like other aldehydes, it can irritate your respiratory system. It's one of the most abundant VOCs in homes, especially those with lots of scented products.

Mold spores are like microscopic seeds that float through the air looking for a damp place to grow. Every home has some mold spores - they're everywhere! But when you have water damage or lots of humidity, these spores can grow into visible mold patches. Breathing in lots of spores is like inhaling thousands of tiny irritants that can make you cough, sneeze, or have asthma attacks.

Dust mites are tiny bugs (too small to see) that live in your bedding, carpets, and furniture. They eat dead skin cells that fall off your body. The problem isn't the mites themselves - it's their poop! Their droppings break down into a powder that gets into the air and makes people with allergies sneeze and wheeze. Imagine millions of invisible bugs pooping in your bed - gross but true!

Carbon dioxide is the gas we breathe out after our bodies use oxygen. In a room with good fresh air coming in, CO2 levels stay low. But in a crowded or poorly ventilated room, CO2 builds up like water filling a bathtub with the drain closed. High CO2 won't poison you like carbon monoxide, but it makes you feel tired, unable to focus, and gives you headaches - like your brain is running in slow motion.

Finding E. coli on surfaces like kitchen counters, cutting boards, or bathroom fixtures means that poop contamination has spread there - either from not washing hands properly, raw meat, or bathroom messes. It's like leaving invisible germs everywhere you touch. These bacteria can make you very sick if they get into your mouth from touching contaminated surfaces and then eating.

Staph bacteria normally live on our skin and in our noses without causing problems - they're like friendly neighbors. But when they get into cuts or wounds, or when there's too much of them on surfaces, they can cause infections. It's spread by touching - like passing a ball from person to person, except the ball is invisible germs. Some staph is antibiotic-resistant (MRSA), making it super dangerous.

Salmonella is a bacteria commonly found on raw chicken and eggs. When you prepare these foods, the bacteria can spread to your cutting board, counter, and anything you touch - like an invisible slime that gets everywhere! If these surfaces aren't cleaned properly and you later prepare food that won't be cooked (like a salad), the bacteria can make you very sick.

When old lead paint chips, cracks, or gets sanded, it creates dust that settles on floors, windowsills, and surfaces. Kids playing on the floor can get this dust on their hands and toys, then put their hands in their mouths - that's how they get poisoned. It's invisible, doesn't wash away easily, and even tiny amounts are dangerous to growing brains. Regular cleaning helps but doesn't remove all of it.

Arsenic on surfaces usually comes from old pressure-treated wood (like decks and playground equipment made before 2004) or contaminated soil tracked indoors. When arsenic-treated wood breaks down, the arsenic dust settles on surfaces. Kids who play on old wooden decks or playgrounds can get arsenic dust on their hands, then transfer it to their mouths when they eat snacks. It's colorless and invisible, making it especially sneaky.

Mercury on surfaces usually comes from broken thermometers, old switches, or fluorescent bulb breakage. When a mercury thermometer breaks, tiny silver beads scatter and can get into carpet fibers or floor cracks. The scary part is that mercury slowly evaporates into the air you breathe - it's like an invisible poison gas rising from those shiny droplets. Even small spills need professional cleanup because mercury is so toxic.

Cadmium can get on surfaces from broken batteries, cheap imported jewelry (especially kids' jewelry), and some old paints. It's like lead's dangerous cousin that doesn't get as much attention but is just as harmful. Kids' metal jewelry has been recalled many times for high cadmium because children put it in their mouths. The dust is invisible and can transfer from contaminated surfaces to hands to mouth.

Chromium on surfaces can come from chromium-6 contamination (the dangerous form), often near industrial sites, or from chromium-treated wood and leather products. While chromium-3 in supplements is safe, chromium-6 is a serious carcinogen. Contaminated dust can settle on surfaces in homes near old industrial areas, especially those with metal plating or leather tanning operations. Cleaning regularly helps reduce exposure.

ATP is like the battery that powers every living cell - from bacteria to food residue to your own skin cells. Testing for ATP is like using a special light to see if a surface is really clean. High ATP levels mean there's lots of biological material (bacteria, food, body fluids) on the surface, even if it looks clean to your eyes. It's used in restaurants and hospitals to verify cleaning.

Black mold is the scary one you hear about on TV! It's a greenish-black mold that grows on materials like drywall and ceiling tiles when they stay wet for a long time. It produces toxins (called mycotoxins) that can make you sick - imagine it as a tiny factory making poison. Not all black-colored mold is Stachybotrys, but when it is, it needs professional removal because disturbing it releases more toxins into the air.

Aspergillus is one of the most common molds found indoors and outdoors. There are many types - some are harmless, but others can cause allergic reactions or infections, especially in people with weak immune systems. It's like having uninvited guests in your house - usually not dangerous, but some can cause problems. It grows on damp walls, in air conditioners, and even in decomposing leaves.

Penicillium is the mold you see on old bread or forgotten oranges - it looks blue or green and fuzzy. While one type of Penicillium gave us the antibiotic penicillin (which is good!), having it growing in your home is not good. It spreads by releasing thousands of spores into the air, like dandelions releasing seeds. These spores can trigger allergies and asthma when you breathe them in.

Ascospores are a whole category of mold spores produced by many different molds, kind of like how 'birds' includes robins, eagles, and sparrows. They come from the sexual reproduction of fungi like Chaetomium and others. They're super common outdoors, especially in warm seasons, and can drift into your home through windows and doors. Most are harmless in small amounts, but high indoor levels compared to outdoor levels can mean you have hidden mold growing somewhere.

Basidiospores come from mushrooms, bracket fungi, and wood-decay fungi - they're basically mushroom 'seeds'! If you have a lot of these indoors, it might mean you have wood rot somewhere in your home, or they're just drifting in from outside. These spores are everywhere in nature, especially in wooded areas. They're like tiny parachutes floating through the air. Most are harmless, but very high indoor levels can indicate wood decay problems.

Cladosporium is the most common mold in the world - it's literally everywhere! It grows on plants (it's called a phylloplane mold), in soil, on window sills, in bathrooms, and pretty much any damp surface. The spores are olive-brown or black and look like tiny chains under a microscope. While it's very common and usually harmless, some people are allergic to it. High indoor levels mean you have moisture problems.

Alternaria spores are some of the biggest mold spores - you can almost see them with the naked eye! They look like little clubs with segments, kind of like a multi-chambered submarine. This mold grows on plants, in soil, and on damp surfaces. It's a major cause of mold allergies - many people who think they have 'hay fever' are actually allergic to Alternaria. It's especially high in late summer and fall.

Finding Chaetomium is like finding a smoking gun for water damage - it almost always means serious, chronic moisture problems! This mold has a distinctive musty, earthy smell and loves to grow on wet drywall, wallpaper, and carpet. It produces structures that look like tiny hairy balls under a microscope. While it's not as toxic as black mold, it's still a strong indicator that you need to find and fix water damage immediately.

Fusarium is a fast-growing mold that loves water - it needs really high moisture to grow, which is both good and bad news. Bad because it means you have serious water problems, good because it won't grow unless things are really wet! It produces toxins and spreads quickly across water-damaged materials. The spores look like little canoes or bananas under a microscope. Some species can infect people with weak immune systems.

Curvularia gets its name from its curved, banana-shaped spores - they literally look bent in the middle! It's a common outdoor mold that grows on plants and in soil, but it can also grow indoors on damp materials. While not as famous as other molds, it can still cause allergies and asthma. In rare cases, it can cause infections in people, especially if they have weak immune systems or existing health problems.

Ulocladium looks very similar to Alternaria under a microscope - they're like cousins. But while Alternaria is common everywhere, finding Ulocladium indoors is a red flag for moisture problems. It needs lots of water to grow, so it's often found with other water-damage molds like Chaetomium and Stachybotrys. Think of it as a water damage detective - where you find it, you'll find serious moisture issues.

Bipolaris and Drechslera are closely related molds that grow on grasses and other plants. Their spores are long and have multiple compartments, kind of like a segmented submarine. They're common in outdoor air, especially in agricultural areas and during growing seasons. While generally not super dangerous, they can cause allergies and, in very rare cases, infections. High indoor levels usually mean outdoor air is getting in.

Epicoccum produces distinctive large, dark, roughened spores that look like little spiky balls or sea urchins under a microscope. It's very common outdoors, growing on dead plants, wood, and in soil. The spores are yellow-orange to reddish-brown and are easy to spot. While it's generally considered low-risk, some people can be allergic to it. Finding lots of it indoors usually just means outdoor air infiltration.

Aureobasidium is a weird mold that starts out pink or cream-colored but turns black as it ages - it's like watching a color-changing toy! It's technically a yeast-like fungus that loves very wet surfaces. You'll often find it as pink or black slimy patches on shower caulking, window sills, and other chronically wet areas. It's more of a nuisance than a health hazard, but it shows you have moisture problems that need fixing.

Scopulariopsis often appears as a chalky, powdery growth on paper, cardboard, and other cellulose-rich materials. Its spores are rough and round, like tiny golf balls under a microscope. While not as common as Aspergillus or Penicillium, it's still found indoors, especially in humid conditions. Some species produce nasty-smelling gases that can damage materials. It can rarely cause nail and skin infections in people.

Lead in soil usually comes from old house paint that chipped off over the years, or from when cars used leaded gasoline (before 1996). This lead doesn't go away - it stays in the soil forever, like glitter that never disappears. Kids playing in the yard can get lead dust on their hands and toys, then accidentally eat it. Gardens near old houses or busy roads often have high lead levels.

Soil pH works just like water pH - it measures if your soil is acidic (like lemon juice), neutral, or alkaline (like baking soda). Different plants like different pH levels, just like some people prefer different temperatures. Blueberries love acidic soil, while vegetables prefer neutral. If your pH is wrong, plants can't absorb nutrients properly - imagine trying to drink a milkshake through a coffee stirrer instead of a straw!

Magnetic fields are invisible forces created by electricity flowing through wires and appliances. They're strongest near power lines, electrical panels, and appliances. Think of them like the invisible force field around a magnet - except these come from electricity. Scientists are still studying whether long-term exposure causes health problems, but high levels near your bed (where you spend 8 hours) are best avoided.

WiFi routers send out invisible radio waves to let your devices connect to the internet - kind of like a radio station broadcasting music. These waves are a type of radiation (but not the nuclear kind). Your phone, laptop, and smart TV all receive these signals. While the radiation is low-power and considered safe by most scientists, some people prefer to turn off WiFi at night or keep routers away from bedrooms.

Chrysotile is the most common type of asbestos, found in about 95% of asbestos products in the US. It was used in everything from roof shingles to floor tiles because it's fireproof and strong. The fibers are curly and flexible, like tiny springs. When materials containing asbestos break down or get disturbed (like during renovation), these microscopic fibers float in the air. Breathing them is like inhaling tiny glass needles that get stuck in your lungs forever.

Amosite, also called brown asbestos, is the second most common type found in buildings. It has straight, brittle fibers that are even more dangerous than white asbestos. It was especially popular in pipe insulation, ceiling tiles, and thermal insulation products because it resists heat extremely well. The fibers are like microscopic needles that, once inhaled, cause inflammation and scarring in your lungs. Amosite is considered more carcinogenic than chrysotile.

A short-term radon test is like taking your temperature when you might be sick - it gives you a snapshot of radon levels right now. The test sits in your basement for 2-90 days collecting air samples. Radon levels can change with weather, seasons, and how much you use your home, so this test might not show the full picture. It's good for a quick check, but a long-term test is more accurate for knowing your true average exposure.

Pollen is like plant sperm - it's how plants reproduce! Trees, grasses, and weeds release billions of tiny pollen grains into the air, and they can drift through your windows and stick to your clothes. Even though pollen is natural, it's one of the biggest causes of allergies. Your immune system mistakes these harmless particles for dangerous invaders and overreacts, causing sneezing, itchy eyes, and runny nose. High pollen days mean staying indoors with windows closed.

Ragweed is the supervillain of allergies! A single ragweed plant can produce a billion pollen grains in one season, and they can travel hundreds of miles on the wind. Ragweed season runs from late summer through fall, and about 15-20% of Americans are allergic to it. The pollen is so light and abundant that it's almost impossible to avoid. If you have fall allergies, ragweed is probably the culprit.

Grass pollen comes from all those lawns, fields, and parks around you. When grass blooms in late spring and summer, it releases tons of pollen - especially after you mow the lawn! The pollen grains are tiny and light, so they float everywhere. If you're allergic and you walk barefoot in grass or lie on the lawn, you might get itchy skin. Grass pollen is one of the most common allergens worldwide.

Tree pollen is usually the first pollen of the year, starting in early spring when trees wake up from winter. Oak, birch, cedar, and pine trees are major culprits. Trees release huge clouds of pollen that can look like yellow-green dust covering cars and sidewalks - that visible yellow stuff is tree pollen! Each type of tree has its own pollen season, so tree allergy season can last months.

Dog dander isn't just the flakes of dead skin your dog sheds - it also includes dried saliva and urine proteins that stick to hair and skin flakes. The main allergen is called Can f 1, a protein found in dog saliva, skin, and hair. When Fido licks himself, the saliva dries and becomes airborne dust. Dog allergen is so sticky and long-lasting that it can remain in homes for months even after the dog is gone!

Cat allergen is even worse than dog allergen! The main culprit is Fel d 1, a protein produced in cat saliva, skin, and sebaceous glands. Cats lick themselves constantly, spreading this protein everywhere. The particles are super tiny and light - they can stay airborne for hours and stick to walls, furniture, and clothes. Cat allergen is found in homes, schools, and offices even where cats have never lived, because people carry it on their clothes!

Cockroach allergen comes from roach droppings, saliva, shed skins, and body parts that break down into dust. The main allergens are proteins called Bla g 1 and Bla g 2 from German cockroaches. This is a huge trigger for asthma, especially in urban areas and apartment buildings. Even after roaches are gone, their allergen remains in dust for a long time. It's one of the main reasons kids in cities have such high asthma rates.

Your house dust contains more bug parts than you'd like to know! Insect fragments include pieces of dead bugs, shed exoskeletons, droppings, and other debris from insects like flies, beetles, and moths. These fragments break down into microscopic particles that become part of household dust. While gross to think about, they're actually a normal part of indoor dust and usually harmless unless you're allergic or have asthma.

Legionella is a bacteria that loves warm water - it grows best in water heaters, hot tubs, and cooling towers between 77-108°F. When you take a shower or use a hot tub, tiny water droplets (mist) go into the air, and you can breathe in the bacteria. It's like the bacteria getting a free ride into your lungs on tiny water parachutes. Most people exposed don't get sick, but it can cause a serious pneumonia called Legionnaires' disease.