PAC Database - Detailed Chemical Data
Chemical Identity
| Chemical | CAS# | UN# | Health Code Numbers | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Ricin | 9009-86-3 |
4.02
4.11
4.06
11.00
|
||||||||||
| Formula | Synonyms | |||||||||||
| [Unknown] | ||||||||||||
Physical Properties
| Mol Wt | State | MP (°C) | BP (°C) | VP (Hg) | VP (°C) | SG | LEL (ppm) |
|---|---|---|---|---|---|---|---|
| 0 | S |
PAC Values
| PAC-1 | PAC-2 | PAC-3 |
|---|---|---|
| 1.8E-05 | 2.0E-04 | 1.2E-03 |
| PAC-1 | PAC-2 | PAC-3 |
|---|---|---|
| 0 | 0 | 0 |
Technical Basis
A review of available sources identified several rat LD50 (inhalation, intraperitoneal, and oral). Note that ricin is on the list of chemicals currently on hold for developing AEGL values . Data sources were selected according to the hierarchy listed in Table 3.1. Toxicity data were selected according to type of exposure, species, and route hierarchies stated in Sections 3.6.3, 3.6.4, and evaluated using factors in Tables 3.2, 3.3, and 3.4. The rat LC50 and rat inhalation LD50 were compared in detail. The rat inhalation LD50 was selected because it was: 1) a more recent study (2015 vs. 1995), and 2) results in a comparable, but slightly more conservative TEEL-3 value compared to the LC50 (3 µg/kg vs. 3.7 µg/kg). Inhalation is the most preferred route, even if it is reported as an LD50. The rat inhalation LD50 dose was reported as a range (3-5 µg/kg,) therefore the lower value was used as the TEEL-3 basis. The TEEL-3 value was calculated as a LD50 in accordance with how it was reported (LD50 adjustment factor of 3.3, see Table 3.4). TEEL-2 and TEEL-1 values were derived according to Table 3.5.
• TEEL-1 = TEEL-2/11
• TEEL-2 = TEEL-3/6
• TEEL-3 = Rat inhalation LD50 (3-5 µg/kg)
This review generated TEEL values that are less conservative than those in Rev. 29A. The Rev. 29A basis, a rat 10-minute LCLo, was not identified during current research.
• TEEL-1 = TEEL-2/11
• TEEL-2 = TEEL-3/6
• TEEL-3 = Rat inhalation LD50 (3-5 µg/kg)
This review generated TEEL values that are less conservative than those in Rev. 29A. The Rev. 29A basis, a rat 10-minute LCLo, was not identified during current research.
References
AEGL list: https://www.epa.gov/aegl/access-acute-exposure-guideline-levels-aegls-values
Approximate molecular weight reported in the NRT Quick Reference Guide: Biotoxins, Ricin, Abrin. Retrieved from https://nrt.org/sites/2/files/NRT%20CBRN%20BIO%20Ricin%20Abrin%20QRG_%20FINAL%202020%2005%2005.pdf
Rat inhalation LD50 (3-5 µg/kg), pg. 15; Scientific Opinion of the Panel on Contaminants in the Food Chain on a request from the European Commission on ricin (from Ricinus communis) as undesirable substances in animal feed. The EFSA Journal (2008) 726, 1–38; https://efsa.onlinelibrary.wiley.com/doi/epdf/10.2903/j.efsa.2008.726
Rat inhalation LD50 (3-5 µg/kg), “Toxicity” section; Moshiri M, Hamid F, Etemad L. Ricin Toxicity: Clinical and Molecular Aspects. Rep Biochem Mol Biol. 2016 Apr;4(2):60-5. PMID: 27536698; PMCID:PMC4986263. https://pubmed.ncbi.nlm.nih.gov/27536698
Rat LD50 (3.7 µg/kg), pg. 3; Griffiths et. al 1995a,b as cited in: Holler, J. (2010, April 13-15). Revisit AEGL for Ricin (CAS Reg. No. 9009-86-3) [Paper presentation]. NAC/AEGL-50 2010. Retrieved from https://www.epa.gov/sites/default/files/2014-04/documents/nac_50_attachments_1_15.pdf
Rat oral LD50 (5-10 µg/kg), pg.2436; Audi J, Belson M, Patel M, Schier J, Osterloh J. Ricin Poisoning: A Comprehensive Review. JAMA. 2005;294(18):2342–2351. doi: https://doi.org/10.1001/jama.294.18.2342