Tar acids, coal, crude

Endpoint summary

Description of key information

Phenol causes severe chemical burns. The local effects are concentration dependent; occasionally skin necrosis was seen in humans with solutions as dilute as 1%. The threshold concentration for local effects in experimental animals is not clearly stated. Irreversible corneal opacity was found in rabbits caused by 5% aqueous phenolic solution. The in vitro study according to OECD Guideline 431 revealed skin corrosive properties. 
Classification: Causes burns (R 34) 

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (corrosive)

Eye irritation

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Additional information

Data were taken from phenol dossier - read across appreach was chosen because the content of phenol in the registered substance could be up to 50% (w/w).

Data on irritation/corrosivity of phenol in experimental animals and humans are presented in EU-RAR (2006), Section 4.1.2.3-4 (page 86ff). The authors concluded that phenol causes severe chemical burns.

 

SKIN IRRITATION/CORROSION

Further testing is scientifically unjustified as existing animal and human data show that the criteria for classification as corrosive to the skin are met.

Mild to severe chemical burns were observed even after a 1-minute uncovered application of undiluted (molten) phenol in five male and five female rats (Brown et al., 1975; see robust study summary in IUCLID Section 7.3.1). The contact of 0.5 g of phenol moistened with physiological saline with the intact and abraded areas of the skin of the bellies of rabbits for a maximum period of 24 hours produced necrosis of the intact skin (limited documentation; Flickinger, 1976, see robust study summary in IUCLID Section 7.3.1). The in vitro study according to OECD Guideline 431 (Slovnaft 2009, see Section 7.3.1) revealed skin corrosive properties.

Phenol has corrosive properties which have been also documented in IUCLID Section 7.2.3 and in the summary of Section 7.2.

 

EYE IRRITATION

According to OECD Guideline 405 no testing is required for corrosive substances. However, the available data in elderly studies confirmed the corrosive properties of phenol (Flickinger, 1976; see robust study summary in IUCLID Section 7.3.2). Rabbits received instillations of 100 mg phenol into the conjuntival sac. Effects were recorded up to 14 days after application. Upon the application the conjunctivae became inflamed, the corneas opaque, and the rabbits gave evidence of marked discomfort. Examination of the exposed eyes 24 hours following exposure showed severe conjunctivitis, iritis, corneal opacities occluding most of the iris, and corneal ulcerations extending over the entire corneal surface. There was almost no perceptible improvement in the condition of the eyes during the observation period, and by the 14th day all of the exposed eyes exhibited keratoconus and pannus formation.

In an eye irritation test 6 rabbits per group were exposed to 0.1 ml of 5% aqueous solution of phenol. In the first group the eyes were washed for 2 minutes with 300 ml of tap water 30 seconds after application and in the second group the eyes remained unwashed. All of the animals produced corneal opacity but washing enhanced the recovery of eyes damaged by phenol and in some cases decreases the severity and duration of corneal opacities. Generally, the effects of the 5% aqueous solution were irreversible after an observation period of 7 days (Murphy et al., 1982; IUCLID Section 7.3.2).

 

HUMAN DATA

Initial skin contact with phenol produces a white wrinkled discoloration with no experience of pain due to the local anaesthetic properties of phenol, with the affected area turning brown and subsequently becoming gangrenous. Ten percent solutions regularly produce corrosion, and occasionally skin necrosis is seen with solutions as dilute as 1% (Kania, 1981; IUCLID Section 7.10.3). Concentrated solutions are severely irritating to the eyes and cause conjunctival swelling with the cornea becoming white and hyperaesthetic; loss of vision has occurred in some cases. Concentration is more critical than volume with respect to local response (Kania, 1981; IUCLID Section 7.10.3).

Effects of 26% phenol in Creolin disinfectant were investigated in 96 cases (Spiller et al. 1993, IUCLID Section 7.10.3). CNS depression was observed in 14%, burns were noted in 24% of orally exposed patients and 26% after dermal exposure. In one case tissue sloughing were observed. All other burns were first degree. It was concluded by the authors that the absence of serious toxicity and major chemical burns in this series does not eliminate concern with the corrosive and systemic risks of phenol poisoning.

In France Eau Phéniquée was used as antiseptic with a phenol content of first 10%, then 5%. Currently there are some antiseptics available with concentrations of phenol up to 1.2%.

Effects on skin irritation/corrosion: corrosive

Effects on eye irritation: corrosive

Justification for classification or non-classification

The available data suggested the following classification: Causes burns (R 34)