Environmental Profiles of Chemical Flame-Retardant Alternatives for

Critical Study:
Type: Acute (24-hour) dermal irritation
Species, strain, sex, number: Rabbit, New Zealand White, 3/sex
Doses: 0.5 mL to each test site (abraded, non-abraded) on each animal
Purity: ~85% Proprietary C in [Formulation 1]
Vehicle: None
Method: Hair was clipped from sides and backs of 6 rabbits; on one side, skin was abraded with
point of 22 gauge needle. The test material was applied occluded; after 1 hour, Elizabethan collars
were used to prevent disturbance of test sites. Sites were cleaned after 24 hours. Sites were
examined for irritation at 26 hours and 72 hours after application.
Results: Males showed no signs of irritation (erythema or edema). No edema was observed in
females. Barely perceptible irritation (erythema) was detected in 2/3 females at 26 hours (mean
scores of 0.3 on intact and 0.2 on abraded skin), but in none at 72 hours; the primary irritation index
was 0.1/8.0. The study authors characterized the material as a “non irritant” to skin following
occlusive exposure for 24 hours.
Reference: Ref. 9
Additional information:
A 4-hour dermal irritation study in rabbits exposed to [Formulation 3] also reported erythema but
no edema, with effects resolving by 48 hours (Ref. 21). No compositional information was available
for this material, but analysis of [Formulation 1] indicated that the [Chemical 1] content was twice
that of [Formulation 1] and its acidity was greater: titration with 1.6 mg KOH/g, compared to 0.1-1.0
mg KOH/g, respectively (Ref. 11). Of two submitted confidential skin irritation studies, one
reported slight irritation (erythema) and another reported mild irritation (erythema and edema).
Skin Sensitization (OPPTS Harmonized Guideline 870.2600; OECD Guideline 429)
Conclusion:
The available skin sensitization data were judged adequate to meet the endpoint.
Basis for Conclusion:
The available studies, two of which indicate no evidence of dermal sensitization and one of which
indicates evidence of mild dermal sensitization, appear to have been consistent with OPPTS and
OECD guidelines. Few details were available for the Buehler test on [Formulation 1] (~85%
Proprietary C), but this method is one considered preferable under OPPTS guideline 870.2600. No
sensitization was reported for [Formulation 2], although analyses suggest that it is less pure than
[Formulation 1], having double the content of [Chemical 1] and slightly greater acidity than the
latter, and containing 1.5-20% [Chemical 2] as a scorch inhibitor (Ref. 11).
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