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==Precautions== Most acids are high risk chemicals. Several precautions are advisable with the stronger acids. These don't all apply to vinegar & citric acid.
- When diluting, never add water to acid, always add acid to water. Doing so is sometimes highly exothermic, and should be done a bit at a time, wearing safety specs. If done the wrong way the result can even progress to explosion sometimes. Exploding boiling acid is not an essential nutrient.
- The stronger acids used in DIY can eat through skin rapidly. Wear suitable gloves
- When holding hold the bottle by the label area, so any unnoticed runs are on the same side, and that's not where you're holding it.
- Don't mix acid with bleach, the resulting chlorine is quite toxic.
- Don't mix acid with alkalis, excess heat is generated, and boiling spitting acid isn't usually a good thing.
- Strong acid plus metal can generate hydrogen, which is explosive at above 4% concentration.
- Suitable gloves & eye protection are sensible for the stronger acids.
- In case of skin contact with strong acids, wash for 10 minutes to minimise burning, chemical reaction & contamination. In case of eye contact, wash well and seek medical help promptly.
==Hydrochloric Acid== [[image:HCl 34% 4168-3.jpg|right|200px]]
- The strongest of all the acids used in DIY
- Also known as spirits of salt, muriatic acid
Uses
- Eats cement & lime
- Cleans cement off bricks etc - but not off cement products
- Can also be used to descale ceramics, but can discolour otherwise unnoticeable surface cracking
Risks
- Destroys cement joints in ceramic pipes
- Strong HCl produces choking fumes and mist
- HCl is highly corrosive to skin, eyes, lungs etc, and toxic. Inhalation of ttoo much of the fumes can cause death
- In case of skin contact, wash for 10-15 minutes. In case of eye contact, wash for 10-15 minutes, lifting both upper & lower eyelids regularly, and seek medical advice without delay.
- Incompatible with many substances
- formatting linkMSDS]
Purchase
- Sold as brick acid, drain unblocker, and is a component of many patio cleaners.
- Available upto 34%
==Sulphuric Acid== [[image:H2SO4 98% 4170-3.JPG|right|200px]] Sulphuric acid has many names, including vitriol, glover acid, tower acid, fertiliser acid, chamber acid, battery acid, dipping acid, mattling acid, electrolyte acid.
Uses
- Eats organic materials rapidly. Eats paper etc in seconds.
- Good for drains where the blockage is organic
- Density of 1.84 means it sinks to the bottom of blockages
- Lead acid batteries use high purity sulphuric acid of around 4M. Less pure drain cleaning acid is not usable for batteries.
- Strong desiccant
- Reaction with sugar produces carbon
- Reaction of hot strong H2SO4 with copper produces copper sulphate, a mould inhibiting antimicrobial.
- Reaction with zinc produces zinc sulphate, a mould inhibiting antimicrobial.
- Used industrially to remove rust
Risks
- Dangerous to skin & eyes
- Destroys cement joints in ceramic pipes
- Toxic
- Strong sulphuric acid can react violently with water
- In work situations all use of sulphuric acid must be assessed under the COSHH regulations.
- formatting linkMSDS]
Purchase
- Upto 98% sulphuric acid is available as drain unblocker.
==Sulphamic Acid== Also known as sulfamic acid, amidosulfonic acid, amidosulfuric acid, aminosulfonic acid, and sulfamidic acid
Uses
- Used to descale heat exchangers in heating systems
- Descale and clean metals and ceramics
- A component in some household descalers & denture tablets
Risks
- Lower risk than hydrochloric acid
Purchase
- Fernox DS-3 contains sulphamic acid, inhibitors, indicators & surfactant.
==Phospohoric Acid== Uses
- Used as rust remover. Turns rust into a stable black ferric phosphate. Often used as a gel preparation to enable it to cling to surfaces at all angles.
- Phospohoric acid is used as a food additive, E338.
- Sometimes used to remove limescale and cement stains.
- Sometimes used as a soldering flux
Risks:
- Don't permit contact with bleach, ammonia or metals
- formatting linkSafety data]
Purchase
- Sold in preparations known as rust convertor, rust remover, rust killer, naval jelly.
==Acetic Acid== [[image:Acetic acid 4159-4.JPG|right|200px]]
- Also known as ethanoic acid, acetyl hydroxide (AcOH), hydrogen acetate (HAc), ethylic acid, methanecarboxylic acid
- Concentrated acetic acid is called glacial acetic acid. It freezes at 16C.
- Acetic acid has a characteristic powerful vinegary smell.
Uses
- Sometimes used with other acids as a descaler
- Food additive E260
- Vinegar is primarily dilute acetic acid, typically around 4-8%
- Vinegar cleans copper, copper alloys, brass, bronze - the runoff is toxic
- Diluted vinegar cleans glass & helps avoid smearing
- Glacial acetic acid is used to remove warts & verrucas, and the dilute acid for ear infections.
- Acetic acid makes copper acetate, a pigment and fungicide.
Risks
- Acetic acid is corrosive, and at high strengths highly flammable.
- Overexposure to the fumes can cause difficulty breathing. This can easily happen at room temperature.
- Symptoms of exposure can be delayed for a few hours.
- Fumes above 39C can be explosive
- Latex gloves don't protect against acetic acid, use nitrile ruber gloves.
- formatting linkSafety info]
==Citric Acid==
- A weak edible acid
Uses
- Citric acid is a widely used food additive, E330
- Descaler for appliances that can't use stronger acids, eg kettles, washing machines etc.
- 2% citric acid makes a handy scale tackling bathroom cleaner. 6% can remove scale without rubbing Salt enhances the descaling action of citric to an extent.
- Appliance descalers in supermarkets are usually citric acid based, and a pricey way to buy the stuff.
- Citric acid can often substitute for lemon juice in recipes
Purchase
- Citric acid is sold as a bagged food additive in some foreign food supermarkets, or less cheaply in small boxes at pharmacies (much used by heroin users).
- Irritant to skin & eyes. In case of eye contact, wash well for 10 minutes and seek medical assistance
- Corrodes copper, zinc, aluminium and their alloys
- formatting linkMSDS]
==See Also==
[[Category:Cleaning]] [[Category:Chemicals]]