4,4'-oxydi(benzenesulphonohydrazide)

Toxicological Summary

Workers - Hazard via inhalation route

Systemic effects

Long term exposure

Hazard assessment conclusion:

DNEL (Derived No Effect Level)

Value:

0.7 mg/m³

Most sensitive endpoint:

repeated dose toxicity

Route of original study:

By inhalation

DNEL related information

DNEL derivation method:

ECHA REACH Guidance

Overall assessment factor (AF):

25

Modified dose descriptor starting point:

NOAEC

Value:

17.6 mg/m³

Explanation for the modification of the dose descriptor starting point:

No inhalational study is available. A NOAEL of 10 mg/kg bw/d from a 90D oral toxicity study is converted to 7.9 mg/m³(10 mg/kg bw/d/0.38 m³/kg bw/d (rat inh vol for 8h) = 26.3 mg/m³and then further modified with a factor 6.7 m³/10 m³due to higher respiration volume during work. The modified starting point is then 17.6 mg/m³

AF for dose response relationship:

1

AF for differences in duration of exposure:

2

AF for interspecies differences (allometric scaling):

1

Justification:

iallometric scaling s not to be used as the dose level has been converted to inhalational concentration

AF for other interspecies differences:

2.5

AF for intraspecies differences:

5

AF for the quality of the whole database:

1

AF for remaining uncertainties:

1

Acute/short term exposure

Hazard assessment conclusion:

no hazard identified

Most sensitive endpoint:

acute toxicity

Route of original study:

By inhalation

DNEL related information

Local effects

Long term exposure

Hazard assessment conclusion:

DNEL (Derived No Effect Level)

Value:

0.1 mg/m³

Most sensitive endpoint:

repeated dose toxicity

DNEL related information

DNEL derivation method:

other: ACGIH OEL value, read-across to hydrazine

Acute/short term exposure

Hazard assessment conclusion:

no hazard identified

Most sensitive endpoint:

acute toxicity

DNEL related information

Workers - Hazard via dermal route

Systemic effects

Long term exposure

Hazard assessment conclusion:

DNEL (Derived No Effect Level)

Value:

0.1 mg/kg bw/day

Most sensitive endpoint:

repeated dose toxicity

Route of original study:

Oral

DNEL related information

DNEL derivation method:

ECHA REACH Guidance

Overall assessment factor (AF):

100

Modified dose descriptor starting point:

NOAEL

Value:

10 mg/kg bw/day

Explanation for the modification of the dose descriptor starting point:

No dermal repeated dose toxicity studies are available. Data from a 90D oral toxicity study (OECD 408) is used where a NOAEL of 10 mg/kg bw/d was identified. As no data regarding skin absorption is available similar absorption after dermal exposes as after oral exposure is assumed as a worst-case scenario.

AF for dose response relationship:

1

AF for differences in duration of exposure:

2

AF for interspecies differences (allometric scaling):

4

AF for other interspecies differences:

2.5

AF for intraspecies differences:

5

AF for the quality of the whole database:

1

AF for remaining uncertainties:

1

Acute/short term exposure

Hazard assessment conclusion:

no DNEL required: short term exposure controlled by conditions for long-term

DNEL related information

Local effects

Long term exposure

Hazard assessment conclusion:

hazard unknown (no further information necessary)

Most sensitive endpoint:

sensitisation (skin)

Acute/short term exposure

Hazard assessment conclusion:

high hazard (no threshold derived)

Most sensitive endpoint:

sensitisation (skin)

Workers - Hazard for the eyes

Local effects

Hazard assessment conclusion:

low hazard (no threshold derived)

Additional information - workers

OBSH is used as a blowing agent in industrial processing and for professional uses.

For systemic effects from long term inhalational exposure, no inhalational study is available. A DNEL of 0.7 mg/m3 was established based on a NOAEL of 10 mg/kg bw/d from an oral OECD 408 90D study.

For local effects in respiratory tract from long term inhalational exposure a DNEL of 0.1 mg/m3 is applicable based on a ACGIH TLV of 0.1 mg/m3 for OBSH derived to protect against effects from hydrazine liberated from hydrolysis of OBSH.

For systemic effects from long term dermal exposure, no dermal study is available. A DNEL of 0.1 mg/kg/d was established based on a NOAEL of 10 mg/kg bw/d from an oral OECD 408 90D study with rats.

Short term exposure is controlled by conditions for long-term exposure, therefore no DNEL has been established. Further, as OBSH has been identified as a skin sensitizer, strict control measures should apply.

General Population - Hazard via inhalation route

Systemic effects

Long term exposure

Hazard assessment conclusion:

no hazard identified

Acute/short term exposure

Hazard assessment conclusion:

no hazard identified

DNEL related information

Local effects

Long term exposure

Hazard assessment conclusion:

no hazard identified

Acute/short term exposure

Hazard assessment conclusion:

no hazard identified

DNEL related information

General Population - Hazard via dermal route

Systemic effects

Long term exposure

Hazard assessment conclusion:

no hazard identified

Acute/short term exposure

Hazard assessment conclusion:

no hazard identified

DNEL related information

Local effects

Long term exposure

Hazard assessment conclusion:

no hazard identified

Acute/short term exposure

Hazard assessment conclusion:

no hazard identified

General Population - Hazard via oral route

Systemic effects

Long term exposure

Hazard assessment conclusion:

no hazard identified

Acute/short term exposure

Hazard assessment conclusion:

no hazard identified

DNEL related information

General Population - Hazard for the eyes

Local effects

Hazard assessment conclusion:

no hazard identified

Additional information - General Population

No hazard identification relevant for consumers and the general population as exposure to OBSH is considered negligible. OBSH is used as a blowing agent and during the foaming process, OBSH during this process decomposes into nitrogen and 4,4-oxybis (benzenesulfonic acid) which is further transformed into polydithiophenyl ether and polymetric thiosulfonate. Therefore, a direct consumer exposure is not likely to occur since OBSH is not contained in final products.