The Home Chemical Almanac · Chapter 4
Bleaches and brighteners
Correct as of November 2026.
If the label says "bleach", "oxygen bleach" or "optical brighteners"
Bleaches break down stains and kill germs. There are two kinds: oxygen bleaches, which release hydrogen peroxide in water, and chlorine bleaches, which release chlorine. Optical brighteners are different again. They don't clean at all: they're fluorescent dyes that stick to fabric so whites look whiter.
In Europe, a detergent label must show oxygen and chlorine bleaches in a percentage band once there's more than 0.2%, and must list optical brighteners whatever the amount. Australian cleaning products don't have to list all their ingredients. Only a scheduled poison must be named on the label, with its strength, and a disinfectant must name its active ingredients.
This chapter also covers ammonia, because it belongs next to bleach for one reason: the two must never meet.
Never mix bleach with anything but water. Australian health advice: "Do not mix bleach with ammonia, acids or other cleaners – this can release hazardous chlorine or chloramine fumes." Acids include vinegar, toilet cleaners and some glass cleaners. Urine contains ammonia, so take care with toilets and nappy buckets. In a US survey, only 58% of adults knew not to mix bleach with ammonia, and only 35% knew not to mix it with vinegar.
Cheat sheet
| Chemical | Badges | Also on labels as | Worst fact | Take care if |
|---|---|---|---|---|
| Sodium percarbonate | ☠ | oxygen bleach, sodium carbonate peroxide | Strong powder can permanently damage eyes | children, eyes |
| Hydrogen peroxide | ☠ | peroxide | A toddler died after swallowing 3% (pharmacy-strength) peroxide | children; never drink it |
| Sodium perborate | 🛢 | perborate | Banned from EU household detergents as toxic to reproduction | pregnant or trying |
| Peracetic acid | ☠ | peroxyacetic acid | Mixed with peroxide, a recognised cause of asthma | asthma, regular use |
| TAED | — | tetraacetylethylenediamine | Reacts with oxygen bleach to make peracetic acid in the wash | — |
| Sodium hypochlorite | ☠ 💧 | bleach, chlorine bleach | 85,104 US chlorine/chloramine gas cases in 8 years | asthma, children, mixing |
| Calcium hypochlorite | ☠ 💧 | pool chlorine, granular chlorine | Can explode if mixed with TCCA tablets and water | children, storage |
| TCCA | ☠ | trichloroisocyanuric acid, chlorine tablets | A little water can make it release chlorine gas | storage |
| Sodium dichloroisocyanurate | ☠ | NaDCC, dichlor | Can cause serious eye damage | eyes, children |
| Ammonia | ☠ | ammonium hydroxide | Mixed with bleach, it makes chloramine gas | asthma, mixing |
| FWA-1 | 🛢 💧 | optical brightener, fluorescent brightener 71 | Australia classes it toxic to aquatic life | — |
| FWA-5 | 🛢 💧 | disodium distyrylbiphenyl disulfonate | Not biodegradable; most ends up in sewage sludge | — |
| Fluorescent brightener 28 | 🛢 | Calcofluor White, FB28 | The same dye labs use to stain fungi | — |
| Fluorescent brightener 220 | — | FB220 | Only 1.2% broke down in 28 days | — |
☠ Poison schedule (Australia) · ⚠ Officially classed skin allergen · 🛢 Made from a hazardous chemical · 💧 Contaminant risk
The chemicals
Part 1: Oxygen bleaches
Part 2: Chlorine bleaches (and ammonia)
- Sodium hypochlorite ☠ 💧
- Calcium hypochlorite ☠ 💧
- Trichloroisocyanuric acid (TCCA) ☠
- Sodium dichloroisocyanurate (NaDCC) ☠
- Ammonia ☠
Part 3: Optical brighteners
All four work the same way. They soak up invisible ultraviolet light and give it back as blue light, which cancels the natural yellowing of fabric. Up to 72% of FWA-1 in the wash sticks to the clothes, and brighteners build up wash after wash. Australia imports 100 to 1,000 tonnes a year of FWA-1, FB28 and FB220 (reported as a group). Australia's regulator classes those three as persistent: they don't biodegrade in water, soil or sediment, and brighteners have been found in Swiss lake mud laid down in the 1950s.
Safer alternatives
Before chlorine, linen was whitened by laying it on the grass in the sun, called crofting, and the whole process could take months. Chlorine bleaching arrived in 1787. In Australia, generations whitened their washing with a bag of Reckitt's Blue, ultramarine and baking soda squeezed into the last rinse.
Look for these instead:
- Sodium percarbonate (oxygen bleach), in place of chlorine bleach for laundry. It's milder, but still a poison above 15%, so keep the powder out of eyes.
- Laundry blue (ultramarine), in place of optical brighteners
- Sunshine for drying whites
- Detergent and water for mould on hard surfaces, then dry it completely
- Brightener-free laundry products, if the label says so
Sources
Regulators and official lists
- Australian Government. Poisons Standard October 2026 (SUSMP), F2026L01327: chlorinating compounds, dichloroisocyanuric acid, hydrogen peroxide, sodium percarbonate, peracetic acid, ammonia.
- Safe Work Australia. Hazardous Chemical Information System (HCIS): classifications for each chemical, and for borax. hcis.safeworkaustralia.gov.au
- AICIS. Evaluation statement EVA00144: Fluorescent Brightener 71 and related chemicals (2023). industrialchemicals.gov.au
- NICNAS. IMAP Tier II assessments: sodium percarbonate (2016); hydrogen peroxide (2014); perborates (2018); peracetic acid (2013). industrialchemicals.gov.au
- ACCC. Analysis of consumer product related calls to the NSW Poisons Information Centre, June 2014 to May 2015 (2016). productsafety.gov.au
- Better Health Channel (Victorian Department of Health). Mould removal at home. betterhealth.vic.gov.au
- Accord Australasia. Hygiene for Health: hygiene product safety (2020). hygieneforhealth.org.au
- NHMRC. Australian Drinking Water Guidelines: chlorate.
- European Union. Regulation (EU) No 109/2012 (perborates in REACH Annex XVII); Detergents Regulation (EC) 648/2004, Annex VII.
- HERA. Risk assessments: sodium percarbonate (2002); hydrogen peroxide (2005); sodium perborate (2002); TAED (2003); FWA-1 (2004); FWA-5 (2003). heraproject.com
- Environment and Climate Change Canada / Health Canada. Screening assessment: Stilbenes Group (2019).
- Nordic Ecolabelling. Laundry detergents and stain removers, criteria and background.
- US FDA. FDA warns consumers against drinking high-strength hydrogen peroxide for medicinal use (2006).
- US EPA. A Brief Guide to Mold, Moisture, and Your Home (EPA 402-K-02-003); Safer Choice Safer Chemical Ingredients List; Chemical Safety Alert: safe storage and handling of swimming pool chemicals (2001).
- US Chemical Safety Board. Bio-Lab Lake Charles TCCA reaction, decomposition and toxic gas release: final report (2023).
- US CDC. Guideline for Disinfection and Sterilization in Healthcare Facilities (2008); Chloramines and pool operation.
- MMWR. Chang et al. 2020;69(16); Gharpure et al. 2020;69(23); Hlavsa et al. 2014;63(19).
- UK Health Security Agency. Sodium hypochlorite: general information (2025); Ammonia: general information (2024).
- US ATSDR. Medical management guidelines for ammonia.
- World Health Organization. Cleaning and disinfection of environmental surfaces in the context of COVID-19 (2020); Chlorine chemical fact sheet (2022).
- ESR (New Zealand). Health risk assessment: household bleach (2015).
Studies
- Atalla et al. Chlorine and chloramine gas exposures reported to US poison centers, 2015–2022. Clin Toxicol 2024;62(9):589-595.
- Hatten BW et al. Outcomes after high-concentration peroxide ingestions. Ann Emerg Med 2017;69(6):726-736.
- Day R et al. Soluble film automatic dishwashing products reported to the UK NPIS 2008–2015. Clin Toxicol 2016;54(9):862-866.
- Hawley B et al. Respiratory symptoms in hospital cleaning staff exposed to a product containing hydrogen peroxide, peracetic acid and acetic acid. Ann Work Expo Health 2017;62(1):28-40.
- Zock JP et al. Domestic use of hypochlorite bleach, atopic sensitization, and respiratory symptoms in adults. J Allergy Clin Immunol 2009;124:731-738.
- Casas L et al. Domestic use of bleach and infections in children. Occup Environ Med 2015;72:602-604.
- Odabasi M. Halogenated volatile organic compounds from the use of chlorine-bleach-containing household products. Environ Sci Technol 2008;42:1445-1451.
- Garcia-Villanova RJ et al. Bromate and chlorate in hypochlorite used for water treatment. Sci Total Environ 2010.
- Pascuzzi TA, Storrow AB. Mass casualties from acute inhalation of chloramine gas. Mil Med 1998.
- Vizcaya D et al. Cleaning products and asthma among cleaning workers. Occup Environ Med 2011.
- Belsito DV et al. Allergic contact dermatitis to detergents. J Am Acad Dermatol 2002;46(2):200-206.
- Victorian Collections (City of Moorabbin Historical Society). "Reckitts" blue bags, 20th C.
- Encyclopaedia Britannica (1911). Bleaching.