Registration Dossier

Administrative data

Description of key information

Six male rabbits were exposed to 0.5 ml of the test material during 4 hours, the patch held in contact with the skin by means of a semi-occlusive dressing. Only very slight erythema in one animal was noted at 60 minutes after removal of the patch.  No other signs of irritation at 24, 48 and 72 hours were observed (Exxon Biomedical Sciences, 1996).
In a study reported without any detail, a 24-hour uncovered application of DIDP (mixed isomers) did not produce any irritating effect on rabbit belly (Smyth et al., 1962).
A study using Lawrence’s method was conducted in 10 mice; undiluted DIDP produced no signs of irritation when administered by the intraperitoneal route (Lawrence et al., 1973).
Primary irritation potential of 0.2 ml of undiluted DIDP was evaluated during a single 24-hour application (occluded patch) on 14 female subjects and 1 male subject. Examinations at 30 minutes and 24 hours after patch removal did not reveal any sign of irritation (Hill Top Research, 1995b cited in Medeiros et al., 1999).
In a briefly reported study, eye injury in rabbits was assessed considering the degree of corneal necrosis that results from instillation of various volumes and concentrations of chemicals. Grade 1 irritation was obtained for DIDP which indicated, at most, a very small area of necrosis resulting from 0.5 ml of undiluted chemical in the eye (Smyth et al., 1962). In a briefly reported study, undiluted DIDP did not produce any obvious irritation (Lawrence et al., 1973).
In a study conducted in 6 rabbits (Industrial Bio-test Laboratories, 1975), undiluted DIDP produced only slight signs of irritation on the conjunctiva at 1, 4 and 24-hour observation times (redness score 1 or 2 and discharge at 1 hour, redness score 1 at 4 hours and redness score 1 in 1 animal at 24 hours). All the eyes were normal at 48, 72 and 96 hours.
No indication of upper airway irritation was reported following acute inhalation exposure in animals. Local irritant effects were reported in rat...

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not irritating)

Eye irritation

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not irritating)

Additional information

Skin: In a study conducted under current testing guidelines, DIDP produced  no or only very slight irritation.  Longer term exposure (24 hours) produced no or at most slight and reversible irritant effects with desquamation.  In humans, there is no indication of an irritating potential.

Conclusion: DIDP is mildly irritating to skin with prolonged exposure.  The irritation observed is minor and does meet requirements for classification.

Eye: DIDP is slightly irritating for rabbit eyes.  The observed effects were redness and chemosis limited to the conjunctiva in a short period after administration.

Conclusion: DIDP may cause mild, short-lasting discomfort to eyes.  The irritation observed is minor and does meet requirements for classification.

Respiratory tract: Based on the absence of evidence of irritation in the eye and skin studies, it may be anticipated that DIDP does not induce respiratory irritation under normal conditions of use.

Conclusion: DIDP is a negligible hazard at ambient normal handling temperatures.

Justification for classification or non-classification