Clinical significance

Industrial exposure to chlorine gas is irritating to mucous membranes, including the conjunctiva, although reports of severe pathology are few. If concentrations are high enough or if duration of exposure is lengthy, fatal outcomes are possible from pulmonary damage. Severe ocular damage in these patients may be masked by the systemic pathology.

The American Association of Poison Control Centers Toxic Exposure Surveillance System database recorded that from 2001–2005 there were over 6000 ocular exposures to hypochlo- rite-containing bleach products. Of these, there were four ‘major’ (indicating some type of significant residual disability) and 522 ‘moderate’ (indicating more prolonged symptoms ­requiring some type of treatment but resulting in no permanent injury) outcomes in their ratings of severity. Unfortunately, this data pull did not detail the specific injuries or define the final outcome in terms of visual acuity or other measure. Typically, ocular splashes from household cleaners containing chlorinated compounds do not result in serious injury. Some chlorinated compounds are made more stable by the addition of alkaline substances and some of the more serious injuries may occur as a result of the elevated pH. Household bleach is usually 5–10% sodium hypochlorite and has a pH near 11.

It is well known that extended ocular exposure to chlorine products in swimming pools will lead to corneal edema and punctate erosions. Higher concentrations of available chlorine in the pool water, the pH and the concentration of chloramines (products of reaction between chlorine and nitrogen-containing compounds such as urea) all affect the degree of irritation.

Chlorine crystals have been reported to form on tonometer tips chronically soaked in bleach solution for anti-sepsis and, despite rinsing of the tips, such crystals may cause minor corneal injury. Although chlorine bleach is an excellent disinfectant, alcohol wiping may be a less problematic method of cleaning tonometer tips. It is important to remind patients to use appropriate eye protection to guard against splash-type injuries while using concentrated cleaning products, including bleach. These products can be corrosive to mucous membranes and substantial irrigation should ensue, and as they are usually quite alkaline, pH testing of the conjunctival cul-de-sac should be tested during irrigation.

Recommendations

1. Industrial ocular exposures to chlorine gas should be treated with copious irrigation, but it is extremely important to immediately­ assess possible pulmonary injury as this can lead to fatal outcomes.

2. Typical ocular splash exposures to bleach should be treated with copious irrigation using sterile water or saline as the pH is typically near 11.

References and Further Reading

American Association of Poison Control Centers Toxic Exposure Surveillance­ System database, 2002–2005, Human ocular exposures by substance. Data pull 8/23/06.

Hery M, Hecht G, Gerber JM, et al. Exposure to chloramines in the atmosphere­ of indoor swimming pools. Ann Occup Hygiene 39(4): 427–439, 1995.

Hery M, Gerber JM, Hecht G, et al. Exposure to chloramines in a green salad processing plant. Ann Occup Hygiene 42: 437–451, 1998.

Horton DK, Berkowitz Z, Kaye WE. The public health consequences from acute chlorine releases, 1993–2000. J Occup Environ Med 44(10): 906–913, 2002.

LoVecchio F, Blackwell S, Stevens D. Outcomes of chlorine exposure: a 5 year poison center experience in 598 patients. Eur J Emerg Med 12: 109–110, 2005.

Martinez TT, Long C. Explosion risk from swimming pool chlorinators and review of chlorine toxicity. J Toxicol Clin Toxicol 33(4): 349–354, 1995.

Mauger TF, Laxson LC. Effect of hydrogen peroxide and sodium hypochlorite­ on the corneal oxygen uptake rate. J Toxicol Cutaneous Ocul Toxicol 11: 369–374, 1992.

Maurer JK, Molai A, Parker RD, et al. Pathology of ocular irritation with bleaching agents in the rabbit low-volume eye test. Toxicol Pathol 29(3): 308–319, 2001.

Racioppi F, Daskaleros PA, Besbelli N, et al. Household bleaches based on sodium hypochlorite: Review of Acute Toxicology and Poison Control Center Experience. Food Chem Toxicol 32(9): 845–861, 1994.

Saunders SK, Kempainen R, Blanc PD. Outcomes of ocular exposures reported to a regional poison control center. J Toxicol Cutaneous Ocul Toxicol 15(3): 249–259, 1996.

Generic name: Hydrogen peroxide.

Synonyms: Hydrogen dioxide hydroperoxide, peroxide, albone, dihydrogen dioxide, hioxyl, inhibine, interox, kastone, oxydol, perhydrol, perone, peroxan.

Proprietary names/products containing: Avail-

able as a generic name product in a variety of laundry bleaches, cleaners and hair dyes.

Primary use

This molecule has many applications in medicine and industry. It is used as an antiseptic, disinfectant and deodorant. It is a strong oxidizing agent that is frequently used to catalyze chemical reactions. Some disinfectant solutions for contact lenses contain 3% hydrogen peroxide. Hydrogen peroxide is used as a 6% solution for wound cleansing, disinfecting equipment, including tonometer tips, and for bleaching hair and fabrics. Some household fabric stain removers and bleaches contain 5–15% hydrogen peroxide. Hydrogen peroxide used for industrial purposes is made in concentrations as high as 90%. Solutions of 90% hydrogen peroxide are also used as rocket fuel.

Ocular side effects

Topical ocular exposure

Certain

1. Irritation – eye pain

2. Cornea – punctate keratitis

3. Conjunctiva – hyperemia

Probable

1.Cornea

a.Haze

b.Edema

c.Ulceration

Possible

1.Cornea

a.Descemet’s membrane detachment

b.Recurrent erosion

Clinical significance

Historically, hydrogen peroxide has been used in eye drops at concentrations up to 20% for the treatment of corneal ulcers without reports of long-term corneal damage. Inadvertent ocular application of 3% solution occurs frequently when contact lens disinfectant solution is mistaken for re-wetting drops. This

Bleaches Class: