Use of this information is subject to copyright laws and may require the permission of the owner of the information, as described in the ECHA Legal Notice.
EC number: 201-052-9
CAS number: 77-73-6
Dicyclopentadiene is considered to be irritating to skin and the respiratory system and slightly irritating to eyes.
irritation scores according to the Draize scheme
Erythema (Test/Control sites)
Oedema (Test/Control sites)
after 1 hour
after 24 hours
after 48 hours
after 72 hours
mean scores 24-72h
Overall mean score (24-72 h)
erythema persisted at all treated skin sites at 24, 48 and 72 hour
observations. Signs of possible hyperkeratinisation were noted on day 7.
No oedema was noted on day 7. No
other adverse dermal reactions were noted during the study.
irritation was assessed in a group of 3 New Zealand white rabbits. 0.5
mL of dicyclopentadiene 75% was applied to an area of clipped, intact
skin under a semi-occlusive dressing for 4 hours. Animals were observed
at 1 and 4 hours after removal of the patch and then daily for 7 days.
Well-defined erythema and slight to severe oedema was present at skin
sites of all rabbits at 24, 48 and 72 hour observations. On day 7 no
oedema was noted but there were signs of possible hyperkeratinisation.
No other adverse dermal reactions were noted during the study. The
overall mean scores (24, 48 & 72 hr) were 2 for erythema and 2.3 for
oedema, and the mean oedema score exceeded 2.3 for two of the three
75% was a therefore considered a moderate irritant to rabbit skin,
therefore, classification as H315 "causes skin irritation", according to
75%: Eye irritation scores according to the Draize scheme
= dulling of corneal surface
Eye irritation was assessed in 3 New Zealand
white rabbits. 0.1 mL dicyclopentadiene 75% was instilled into the
conjunctival sac and the eyes were scored for irritation responses at 1,
24, 48 and 72 hours and at 7 days after instillation. At 1 hour, corneal
dulling was present in 2 eyes, iridial inflammation and moderate
conjunctival irritation were present in all 3 eyes, giving an overall
mean score of 18.5 at 1 hour, which corresponds to moderate irritation
(Kay and Callandra, 1962). Signs of irritation regressed to minimal in 2
eyes at 24 hours but persisted in 1 animal at 48 and 72 hours. All
effects were fully reversible within 7 days. Dicyclopentadiene 75% was a
moderate irritant to the rabbit eye at 1 hour but was practically
non-irritating at 24, 48 and 72 hours. According to GHS / CLP labelling
regulations dicyclopentadiene is a non-irritant and requires no symbol
or risk phrase.
In what is
considered to be the key skin irritation study in New Zealand White
rabbits (Safepharm, 1989c) 0.5 mL of dicyclopentadiene 75% was applied
to an area of clipped, intact skin under a semi-occlusive dressing for 4
hours. Animals were observed at 1 and 4 hours after removal of the patch
and then daily for 7 days. Well-defined erythema and slight to severe
oedema was present at all sites and for all rabbits at 24, 48 and 72
hour observation times. On day 7, no oedema was noted but there were
signs of possible hyperkeratinisation. No
other adverse dermal reactions were noted during the study. The overall
mean scores (24, 48 and 72 h) were 2 for erythema and 2.3 for oedema;
dicyclopentadiene 75% was a therefore considered to be a moderate
irritant of rabbit skin.
an older supporting study. New
rabbits were used to assess skin irritation following a 24 hour,
uncovered, application of 0.01 mL undiluted dicyclopentadiene (Smyth
overall irritation score (on a scale of 1 -10) was 5 and confirmed that
undiluted dicyclopentadiene was moderately irritating to rabbit skin.
In what is
considered to be the key eye irritation study in New Zealand White
rabbits (Safepharm 1989d) 0.1 mL dicyclopentadiene 75% was instilled
into the conjunctival sac and the eyes were scored for irritation
responses at 1, 24, 48 and 72 hours and at 7 days after instillation.
Moderate irritation was present at 1 hour in all 3 rabbit eyes; iridial
inflammation and conjunctival irritation were present in all cases and
corneal dulling was present in 2. However, signs of irritation regressed
to minimal in 2 eyes at 24 hours. Although
corneal redness persisted in 1 animal at 72 hours, all effects were
fully reversible within 7 days.
a supporting study (Litton Bionetics, 1976a) using undiluted
dicyclopentadiene, initial conjunctival irritation was present in 7 out
of 9 rabbits but had recovered by day 3. Undiluted dicyclopentadiene was
practically non-irritating at 24, 48 and 72 hours in this study.
there are no specific studies assessing respiratory irritation,
laboured/ irregular breathing, nasal discharge and haemorrhagic lungs
post mortem were evident in acute inhalation exposures of rats and mice
(Bushy Run, 1981) and dose-dependent eye irritation was observed in a
variety of species during acute inhalation exposures to neat
dicyclopentadiene vapour (Kinkead et al, 1971).
little information has been reported on the irritation effects of
dicyclopentadiene in humans. However, in a study in volunteers to
determine the human sensory response to dicyclopentadiene vapour, 2
subjects inhaled analysed concentrations of 1 ppm and 5.5 ppm for 30
minutes (Kinkead et al, 1971). Both concentrations caused sporadic eye
and throat irritation and one subject could taste dicyclopentadiene for
1 hr after the 5.5 ppm exposure. Human exposure to vapours of
dicyclopentadiene is considered likely to result in respiratory and
ocular irritation. The literature was reviewed (Amoore et al, 1983) to
provide quantitative data on the odour thresholds of 214 chemicals
including dicyclopentadiene. Data on the volatility, solubility,
ionisation and water-air distribution ratio at 25ºC were collected and a
safe dilution factor and an odour safety factor were calculated. For
dicyclopentadiene the threshold limit value was 5 ppm v/v, the
volatility at 25ºC was 3600 ppm v/v, the air odour threshold was
0.0057±1.9 ppm. The
calculated safe dilution factor was 720 and the odour safety factor was
870. On the basis of these results, dicyclopentadiene was placed in
odour safety class A (i. e. more than 90% of distracted persons
perceived warning of TLV concentration in the air).
Effects on skin irritation/corrosion:
Effects on eye irritation: slightly irritating
Effects on respiratory irritation: irritating
studies of both undiluted dicyclopentadiene and dicyclopentadiene 75%
demonstrate moderate skin irritation and justify the classification of
Category 2 (Irritant) with the hazard statement" H315 causes skin
irritation" under CLP.
In the key
study of eye irritation, dicyclopentadiene 75% was non-irritant but undiluted
dicyclopentadiene showed slight eye irritation in a supporting study.
Maintenance of the classification as Category 2 "H319 Causes serious eye
irritation" under CLP
observations of respiratory tract irritation in animals and humans means
that dicyclopentadiene warrants classification as Category 3 for
transient target organ toxicity under STOT-RE under CLP.
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
Welcome to the ECHA website. This site is not fully supported in Internet Explorer 7 (and earlier versions). Please upgrade your Internet Explorer to a newer version.
Do not show this message again